I heard a story of a church that lent their space to their Muslim neighbors to be used for worship. They saw that action as a good witness to their neighbors. Many thoughts came to my head upon hearing this. I imagined one day walking to our church and seeing in one of our classrooms, a puja (worship which includes sacrifice of some food) conducted for a Hindu god. I would be shocked. Imagine if the puja takes place in the sanctuary itself. I would be flabbergasted.   

     I thought about the issues. One issue is that a Christian church building is supposedly dedicated to the worship of Jesus. Does Jesus commend this dedication of a place for his worship? Well, the extravagant show of love by one of his followers (pouring expensive perfume on him), was commended by him, so we could not use the argument that this devotion to Jesus (dedicating a place for his worship) is wrong. This Christian church has ceased to become dedicated to the worship of Jesus, therefore should not be called a Christian church anymore. The honest thing to do for this church is to cease to call their church building a Christian church, and donate it to the community as a chapel for generic worship, like a hospital chapel.     

     Now they may argue that Muslims worship the same God the father. That is debateable and even if that is true, Muslims deny Jesus' claim to deity, which makes them disobedient to the God who lifted up his son to be worshipped. Then this Christian church could be accused of condoning disobedience to God in its premises, which is completely different from inviting "sinners" to meet Jesus. Jesus met with sinners but he did not condone their sins. This is also different from using Christian churches for things other than worship, like for polling places. That is not condoning sin.      

     Another issue is that Jesus wanted God's place of worship, the temple, to be solely a house of prayer for people who are seeking Yahweh. Jesus was furious that business was conducted in the temple. A case can be made that the Christian church should be a place to meet Jesus, the God of Christians, not a generic place of worship. It should also not be a social club where people principally seek connections for their business or for personal reasons. It could be argued though that Jesus is now the place we meet God, and to designate a place that way is sacreligious. The early christians did not make buildings but worshipped in synagogues or in houses.