The issue seems to be what Muslims believe about Jesus Christ. My question would be: "What does your sister-in-law not believe about Jesus that keeps her from becoming a Christian?

Two things in the End of the Spear movie make it useful for dialog with Muslims about problems we are experiencing from published cartoons of Mohammed.

More and more Muslims are having dreams and visions of Christ, Christian ministries say. There is increasing evidence that the supernatural is playing a role in drawing Muslims to Christ.