There are very few Biblical passages that promote tolerance, in comparison with its many instances of religious intolerance.
We could only find one reference in the Hebrew Scriptures (Old Testament) - and it was a vague prophecy about religious peace, at some undefined time in the future. There are only a handful of examples in the Christian Scriptures (New Testament). Most of them deal with tolerance by one Christian to another.
An overall theme of the Bible is religious exclusivity and intolerance.
Religious Tolerance in the Hebrew Scriptures:
World religions at peace with each other: The prophet Micah prophesied about a coming time when nations will stop making war. The various peoples of the world will live in peace and pursue their different religions, each worshipping their different Gods and Goddesses. Meanwhile, the Jews will continue to follow Jehovah. His prophesy came to pass for the known western world during the Roman Empire where religious were generally tolerated (except for the intermittent persecution of Christians). There has not been any period since the fall of the Roman Empire when tolerance of religious minorities has been generally observed worldwide.
"...they shall beat their swords into plowshares, and their spears into pruning hooks: nation shall not lift up a sword against nation, neither shall they learn war any more. But they shall sit every man under his vine and under his fig tree; and none shall make them afraid: for the mouth of the LORD of hosts hat spoken it. For all people will walk every one in the name of his god, and we will walk in the name of the LORD our God for ever and ever." (KJV)
Religious Tolerance in the Christian Scriptures (New Testament):
Tolerance of other types of "Christianity": Jesus' disciples had rejected a healer who was exorcising demons in Jesus' name, yet was not one of Jesus direct followers. Jesus criticized his disciples and accepted the healer. Mark and Luke report the incident in parallel passages:
Mark 9:38-40 "...we saw one casting out devils in thy name, and he followeth not us: and we forbade him, because he followeth not us. But Jesus said, Forbid him not: for there is no man which shall do a miracle in my name, that can lightly speak evil of me. For he that is not against us is on our part." (KJV)
Luke 9:49-50 "...we saw one casting out devils in thy name; and we forbade him, because he followeth not with us. And Jesus said unto him, Forbid him not: for he that is not against us is for us."
Jesus refused to curse non-believers: Jesus' teachings were rejected by the inhabitants of a village in Samaria. His disciples asked that he exterminate the people of the village by issuing a curse. Jesus refused to do it, and simply move on to the next village.
Luke 9:52-56: "...they did not receive him...And when his disciples James and John saw this, they said, Lord, wilt thou that we command fire to come down from heaven, and consume them, even as Elias did? But he turned, and rebuked them, and said, Ye know not what manner of spirit ye are of. For the Son of man is not come to destroy men's lives, but to save them. And they went to another village."
Jesus treats a Samaritan women with respect: Jesus initiates a conversation with a Samaritan woman in Sychar, Samaria. This is unusual in at least two ways: Jewish men did not talk to women who were not their wives or were not from their family. Also, Jews normally treated Samaritans with contempt. Jews did not have dealings with them, because they had deviated from Judaism.
John 4:7-27: "There cometh a woman of Samaria to draw water: Jesus saith unto her, Give me to drink...Then saith the woman of Samaria unto him, How is it that thou, being a Jew, askest drink of me, which am a woman of Samaria? for the Jews have no dealings with the Samaritans. Jesus answered and said unto her, If thou knewest the gift of God, and who it is that saith to thee, Give me to drink; thou wouldest have asked of him, and he would have given thee living water...Jesus saith unto her, Woman, believe me, the hour cometh, when ye shall neither in this mountain, nor yet at Jerusalem, worship the Father...And upon this came his disciples, and marveled that he talked with the woman..."