Exclusivism is built into the DNA of the New Testament:
“And calling the crowd to him with his disciples, he said to them, ‘If anyone would come after me, let him deny himself and take up his cross and follow me. For whoever would save his life will lose it, but whoever loses his life for my sake and the gospel's will save it. For what does it profit a man to gain the whole world and forfeit his soul? For what can a man give in return for his soul? For whoever is ashamed of me and of my words in this adulterous and sinful generation, of him will the Son of Man also be ashamed when he comes in the glory of his Father with the holy angels.’”
– Mark 8:34-38
“And he said to them, ‘Go into all the world and proclaim the gospel to the whole creation. Whoever believes and is baptized will be saved, but whoever does not believe will be condemned.’”– Mark 16:15-16
“Whoever is not with me is against me, and whoever does not gather with me scatters.”– Matthew 10:30
”…everyone who acknowledges me before men, I also will acknowledge before my Father who is in heaven, but whoever denies me before men, I also will deny before my Father who is in heaven.”– Matthew 10:32-33
“Do not think that I have come to bring peace to the earth. I have not come to bring peace, but a sword. For I have come to set a man against his father, and a daughter against her mother, and a daughter-in-law against her mother-in-law. And a person's enemies will be those of his own household. Whoever loves father or mother more than me is not worthy of me, and whoever loves son or daughter more than me is not worthy of me. And whoever does not take his cross and follow me is not worthy of me. Whoever finds his life will lose it, and whoever loses his life for my sake will find it.”– Matthew 10:34-39
“All things have been handed over to me by my Father, and no one knows the Son except the Father, and no one knows the Father except the Son and anyone to whom the Son chooses to reveal him.”– Matthew 11:27
“And Jesus came and said to them, ‘All authority in heaven and on earth has been given to me. Go therefore and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, teaching them to observe all that I have commanded you.’”– Matthew 28:18-20
“Jesus answered him, ‘Truly, truly, I say to you, unless one is born again he cannot see the kingdom of God.’”– John 3:3
“And as Moses lifted up the serpent in the wilderness, so must the Son of Man be lifted up, that whoever believes in him may have eternal life.”– John 3:14
“For God so loved the world, that he gave his only Son, that whoever believes in him should not perish but have eternal life. For God did not send his Son into the world to condemn the world, but in order that the world might be saved through him. Whoever believes in him is not condemned, but whoever does not believe is condemned already, because he has not believed in the name of the only Son of God.”– John 3:16-18
“Whoever believes in the Son has eternal life; whoever does not obey the Son shall not see life, but the wrath of God remains on him.”– John 3:36
“Jesus said to them, ‘I am the bread of life; whoever comes to me shall not hunger, and whoever believes in me shall never thirst. But I said to you that you have seen me and yet do not believe. All that the Father gives me will come to me, and whoever comes to me I will never cast out. For I have come down from heaven, not to do my own will but the will of him who sent me. And this is the will of him who sent me, that I should lose nothing of all that he has given me, but raise it up on the last day. For this is the will of my Father, that everyone who looks on the Son and believes in him should have eternal life, and I will raise him up on the last day.’”– John 6:35-40
“Again Jesus spoke to them, saying, ‘I am the light of the world. Whoever follows me will not walk in darkness, but will have the light of life.’”– John 8:12
“So Jesus again said to them, ‘Truly, truly, I say to you, I am the door of the sheep. All who came before me are thieves and robbers, but the sheep did not listen to them. I am the door. If anyone enters by me, he will be saved and will go in and out and find pasture.’”– John 10:7-9
“Jesus said to her, ‘I am the resurrection and the life. Whoever believes in me, though he die, yet shall he live, and everyone who lives and believes in me shall never die. Do you believe this?’”– John 11:25-26
“Jesus said to him, ‘I am the way, and the truth, and the life. No one comes to the Father except through me.’”– John 14:6
“I am the true vine, and my Father is the vinedresser. Every branch in me that does not bear fruit he takes away, and every branch that does bear fruit he prunes, that it may bear more fruit. Already you are clean because of the word that I have spoken to you. Abide in me, and I in you. As the branch cannot bear fruit by itself, unless it abides in the vine, neither can you, unless you abide in me. I am the vine; you are the branches. Whoever abides in me and I in him, he it is that bears much fruit, for apart from me you can do nothing.”– John 15:1-5
“Now Jesus did many other signs in the presence of the disciples, which are not written in this book; but these are written so that you may believe that Jesus is the Christ, the Son of God, and that by believing you may have life in his name.”– John 20:30-31
“And Peter said to them, ‘Repent and be baptized every one of you in the name of Jesus Christ for the forgiveness of your sins, and you will receive the gift of the Holy Spirit.’”– Acts 2:38
“And the Lord added to their number day by day those who were being saved.”– Acts 2:47
“This Jesus is the stone that was rejected by you, the builders, which has become the cornerstone. And there is salvation in no one else, for there is no other name under heaven given among men by which we must be saved.”– Acts 4:11-12
“And he commanded us to preach to the people and to testify that he is the one appointed by God to be judge of the living and the dead. To him all the prophets bear witness that everyone who believes in him receives forgiveness of sins through his name.”– Acts 10:42-43
“And I said, ‘Who are you, Lord?’ And the Lord said, ‘I am Jesus whom you are persecuting. But rise and stand upon your feet, for I have appeared to you for this purpose, to appoint you as a servant and witness to the things in which you have seen me and to those in which I will appear to you, delivering you from your people and from the Gentiles—to whom I am sending you to open their eyes, so that they may turn from darkness to light and from the power of Satan to God, that they may receive forgiveness of sins and a place among those who are sanctified by faith in me.’”– Acts 26:15-18
“Therefore, since we have been justified by faith, we have peace with God through our Lord Jesus Christ. Through him we have also obtained access by faith into this grace in which we stand…”– Romans 5:1-2
“…if you confess with your mouth that Jesus is Lord and believe in your heart that God raised him from the dead, you will be saved.”– Romans 10:9
“Therefore, if anyone is in Christ, he is a new creation. The old has passed away; behold, the new has come. All this is from God, who through Christ reconciled us to himself and gave us the ministry of reconciliation; that is, in Christ God was reconciling the world to himself, not counting their trespasses against them, and entrusting to us the message of reconciliation.”– 2 Corinthians 5:17-18
“We ourselves are Jews by birth and not Gentile sinners; yet we know that a person is not justified by works of the law but through faith in Jesus Christ, so we also have believed in Christ Jesus, in order to be justified by faith in Christ and not by works of the law, because by works of the law no one will be justified.”– Galatians 2:15-16
“For as many of you as were baptized into Christ have put on Christ. There is neither Jew nor Greek, there is neither slave nor free, there is no male and female, for you are all one in Christ Jesus. And if you are Christ's, then you are Abraham's offspring, heirs according to promise.”– Galatians 3:27-29
“In him we have obtained an inheritance, having been predestined according to the purpose of him who works all things according to the counsel of his will, so that we who were the first to hope in Christ might be to the praise of his glory. In him you also, when you heard the word of truth, the gospel of your salvation, and believed in him, were sealed with the promised Holy Spirit, who is the guarantee of our inheritance until we acquire possession of it, to the praise of his glory.”– Ephesians 1:11-14
“For through him we both have access in one Spirit to the Father. So then you are no longer strangers and aliens, but you are fellow citizens with the saints and members of the household of God, built on the foundation of the apostles and prophets, Christ Jesus himself being the cornerstone…”– Ephesians 2:18-20
“For his sake I have suffered the loss of all things and count them as rubbish, in order that I may gain Christ and be found in him, not having a righteousness of my own that comes from the law, but that which comes through faith in Christ, the righteousness from God that depends on faith…”– Philippians 3:8-9
“For they themselves report concerning us the kind of reception we had among you, and how you turned to God from idols to serve the living and true God, and to wait for his Son from heaven, whom he raised from the dead, Jesus who delivers us from the wrath to come.”– 1 Thessalonians 9:10
“…when the Lord Jesus is revealed from heaven with his mighty angels in flaming fire, inflicting vengeance on those who do not know God and on those who do not obey the gospel of our Lord Jesus. They will suffer the punishment of eternal destruction, away from the presence of the Lord and from the glory of his might…”– 2 Thessalonians 1:7-9
“For we have come to share in Christ, if indeed we hold our original confidence firm to the end.”– Hebrews 3:14
“Since then we have a great high priest who has passed through the heavens, Jesus, the Son of God, let us hold fast our confession.”– Hebrews 4:14
“Beloved, do not believe every spirit, but test the spirits to see whether they are from God, for many false prophets have gone out into the world. By this you know the Spirit of God: every spirit that confesses that Jesus Christ has come in the flesh is from God, and every spirit that does not confess Jesus is not from God. This is the spirit of the antichrist, which you heard was coming and now is in the world already. Little children, you are from God and have overcome them, for he who is in you is greater than he who is in the world. They are from the world; therefore they speak from the world, and the world listens to them. We are from God. Whoever knows God listens to us; whoever is not from God does not listen to us. By this we know the Spirit of truth and the spirit of error.”– 1 John 4:1-6
“Everyone who believes that Jesus is the Christ has been born of God, and everyone who loves the Father loves whoever has been born of him.”– 1 John 5:1
“Whoever has the Son has life; whoever does not have the Son of God does not have life.”– 1 John 5:12
The message is clear. If you don’t accept Jesus, you are not part of the people of God. And not only that, but in the most extreme theologies of the New Testament, you are destined for hell.
I believe that the historical Jesus, represented most clearly in the synoptic Gospels, equated allegiance with himself as allegiance with God because he thought himself to be the final God-ordained prophet before imminent arrival of the eschatological kingdom of God. As with Jesus, so with his followers, as the rest of the New Testament continues to make the exclusivistic claim that to accept Jesus is the only way to authentically accept God. Thom Stark, in The Human Faces of God, makes the same observation, and claims that these beliefs, at least in part, stem from the apocalyptic worldview that Jesus and his followers inherited:
"The apocalyptic worldview divides up the entire cosmos into two categories: good and evil, or light and dark. Those on the side of light have given their allegiance wholly to God; everyone else, wittingly or not, has given their allegiance to Satan. Because of Jesus’ conviction that he was the last prophet before the imminent end of the world, Jesus was able to equate allegiance to himself with allegiance to God. As with other apocalyptic sects of his day (such as the Qumran community), Jesus believed that his brand of Judaism was the only brand that could save the people of Yahweh from the coming destruction and judgment. Of course, this black and white perspective is understandable given the character of the times. Apocalyptic Jews considered themselves to be soldiers (some violent, others nonviolent) in a time of war... In wartime it is often necessary to draw up sharp dividing lines between sides in the conflict, and this would have been the logic that underwrote apocalyptic sects’ extreme claims that failure to join their particular cause was tantamount to treason. Only the narrow road leads to life, but broad is the road that leads to destruction."
If the reconstruction of the historical Jesus as "apocalyptic prophet" is correct, then Jesus was mistaken. The eschatological kingdom did not come.
One implication of taking this view is that Jesus’ teaching, and the teaching of the New Testament as a whole, becomes relativized. If Jesus was wrong on one thing, he could be wrong on many things. His theology, his ethics (let alone Paul’s theology and Paul’s ethics), should be accepted or rejected on their own merits, because they appeal to one’s reason or conscience, not because of a default (and orthodox) understanding that everything Jesus says, by definition, must be correct. This doesn’t mean that all of Jesus’ teaching should be rejected, but it does mean that Christians should engage with that teaching in a different way.
And the salvation of one’s soul ceases to be dependent on accepting Jesus as Lord.
These implications follow if one adopts a non-orthodox view of who Jesus was as a historical figure. It is very difficult, in my view, for one to accept an orthodox picture of the historical Jesus, say that of N.T. Wright, and also honestly accept religious pluralism. To do so cuts across the grain of a wide swath of Christian scriptures, and seemingly of the teaching of Jesus himself.
Of course many Christians have no desire to accept religious pluralism. To do so, in fact, is often seen as a “selling out,” a diluting of one’s faith.
For me, after meeting my Jewish, Muslim, Hindu, Buddhist, (and agnostic and atheist) neighbors, it’s a necessity. We are just too much alike to say that Christians are the only group of people who experience God in a real way. The insider/outsider dynamic created by conservative Christian theology is just too hard to reconcile with our modern, real-life experience.