This week's question comes from Dave in Wyoming who asks, "What should a Christian's attitude be toward those of other religions? Do we have a responsibility to try to challenge and change their beliefs, or should we just offer our perspectives if they seem interested in learning about what we believe?"
In the wide realm of Christianity there are different answers, depending on one's belief system. Orthodox Christianity holds that someone's eternal resting place, that is, heaven or hell, is determined by faith in Jesus. To that end, missionaries were sent worldwide to "convert" the heathens (meaning anyone who didn't believe like they did). The missionary movement is as ancient as Christianity itself. Paul's journeys through Asia Minor were for the distinct purpose of spreading the gospel to both the Jewish and the non-Jewish people. However, the methods used to share the gospel changed dramatically by the Middle Ages.
The early church presented the gospel wherever it could get a hearing. Acts 2 records Peter sharing the gospel with a crowd who'd gathered outside the house the disciples were staying in. In Acts 8 we read of Philip teaching a traveling Ethiopian who had asked about the meaning of scripture. In Athens, Paul addressed a crowd at a temple and shared the gospel by comparing God to one of the Athenian gods (Acts 17). On another occasion, Paul was imprisoned and had the opportunity to share the gospel with King Agrippa (Acts 26). But in each case, the gospel story was this: Jesus is the messiah, the son of God, and people should repent of the sin in their lives and do good deeds. It wasn't: Believe or else. . . .
However, by the fourth century the church began to change its methods. Augustine interpreted Luke 14.33 "So therefore, none of you can become my disciple if you do not give up all your possessions" as a passage endorsing force against those who were heretical. By the Middle Ages the church had sent pilgrims to Jerusalem to slaughter the Muslims, thus beginning the Crusades. In the twelfth century the inquisition began and over the next 700 years the church killed thousands who didn't believe "correctly." All this in the name of conversion to orthodox Christianity.
Since then, human rights have come to outweigh the demands of orthodoxy and conversion methods changed. However, the motivation to convert people to orthodox Christianity remains the same: without belief in Jesus there can be no eternal life. This doctrine provides the impetus to challenge the belief systems of others "for their own good."
But there are others who are uncomfortable with the orthodox church's tenets. They look at scripture through different eyes and with a different interpretation. They take the words of Paul to heart when he says, "For what can be known about God is plain to [those who have not heard/accepted the gospel], because God has shown it to them. Ever since the creation of the world God's eternal power and divine nature, invisible though they are, have been understood and seen through the things God has made" (Romans 1.19-20). In other words, we can and do know God apart from the scriptures. Further, Paul wrote in Romans 11 that all those of the Jewish faith shall be saved, for "as regards election they are beloved for the sake of their ancestors; because the gifts and the calling of God are irrevocable" (Romans 11.28b-29). Thus, there is more than a single way to be faithful to God. Those who look at these and other passages, at the content of the ancient church's preaching, and at the teachings of Jesus himself, conclude that we cannot know everything there is to know about God or about "salvation." And so they share the gospel with those who are interested and/or with those who are receptive.
Which way is "right"? Jesus commissioned his disciples to go and make more disciples. It is a mandate all Christians carry. But the question remains, should we spend our time challenging the beliefs of others with a view to converting them, or should we reach out to those who are receptive to the gospel because of curiosity, the movement of the Spirit, or because of need. Our answer is found within our own beliefs. But no matter which doctrine we choose, we are all commissioned to share the gospel -- the only question is, who are you going to share it with?