23 but we preach Christ crucified: a stumbling block to Jews and foolishness to Gentiles, 24 but to those whom God has called, both Jews and Greeks, Christ the power of God and the wisdom of God. 25 For the foolishness of God is wiser than human wisdom, and the weakness of God is stronger than human strength. 1 Corinthians 1:23-25
When discussing religion with Muslims, the cross is the clear distinction between what Christians believe about Jesus and what Muslims believe. It’s easy to talk about any other issues and beliefs regarding either religion, but when you get to the cross, there is no compromise.
I recall a scenario where I was speaking with several Muslims about religion and getting heated about a topic. Later, an Egyptian Christian brother who was in the same room listening to the discussion, said to me, “David, if at all possible stick to the cross. They have no answer to the cross.”