John 14:6 states "Jesus said to him, “I am the way, and the truth, and the life. No one comes to the Father except through me."
This verse has long been quoted as the definitive proof that the only way to salvation is to become Christian. Of course if becoming Christian is the exclusive path to salvation, then we have a moral obligation to convince everyone to become Christian by any means possible. This understanding has been the underpinning of Church outreach for centuries. Never mind that for those same centuries Church mission most often went hand in hand with conquest by the Western country that sponsored the mission.
When the British missionaries arrived in India, they discovered that there was already a thriving church there. It had been founded, according to tradition, by St. Thomas. Since it didn't look like the Christianity the missionaries were used to they at best ignored it and at worst tried to shut it down and replace it with the more acceptable British version.
We still do this. Indigenous people apparently have no ability to worship correctly, so we need to send out our own people to keep them in line and make sure they are orthodox. When we do this we are being hypocrites of the highest order. The modern church is the accretion of centuries of people bringing their own cultures and beliefs to the faith. Just because we are happy with where we are doesn't mean that the process will or should stop.
There are groups that are doing great things in the name of Christ, but I cringe whenever I hear the motivation for mission as "All those millions of people are going to Hell if we don't convert them." I don't worship a God who would send anyone to Hell unless the person truly desired to go there. The Gospels are pretty clear that Jesus died for all people. They don't say "all people who have a right and correct belief and say the proper version of the sinner's prayer". That's our stuff not God's.
So what is Jesus saying when he says "I am the Way, the Truth, and the Life. No one comes to the Father but through me."? Let's back up a bit to see who John says Jesus is. John 1 says "In the beginning was the Word, and the Word was with God, and the Word was God." Later the Word becomes flesh and dwells among us. That Word made flesh is called Jesus. It is the Word that created who is the Way, the Truth, and the Life. In John, when Jesus makes the "I am" pronouncements he is speaking as the Word. I am Bread, I am Light, I am the Gate, I am the Good Shepherd, I am the Resurrection, I am the Way, I am the Vine. In each of these statements he is highlighting a way in which he reconciles the world to God.
These are not statements of exclusion, but rather radical inclusion. He is bread to any who hunger, light to those who need to see, the safe gate to refuge, the one who cares for the lost, hope for the dead, and the path to God, the one in whom we are connected to life. None of these things depend on us. We can't make Jesus and more or less Bread.
So what is our mission? We are to live our relationship with God through Jesus. We are, in our frailties, to incarnate the love of God in our lives. Following Jesus we too become bread, light, freedom, care, hope, guidance, and life. If people want to join us. Great. If the don't, they still belong to God.
We can listen with respect to the stories of other faiths, and tell our story with respect in turn. But our real task isn't in the talking, but the living.