[2 Corinthians 12:21] [Colossians 3:5]

This may shed some light on how God feels about fornication... but in the old testiment adultry and fornication is the same thing... Something about the translation between Greek, Hebrew and English. 

Are they Christian??

I ask because first, if they are, they may listen (with the word of God behind it) and if they are not Christian... then no amount of preaching from the Bible will "make them" listen since they have no Holy Spirit living inside them...

Like in [Romans 1] it talks about going down a road of futile thoughts and vain imaginagitions (sp) then to sexual sin then to homosexual sin... "God gave them over..." to all sorts of sin...

You might want also to look at how Pharo (Moses and Pharo) hardend his heart and then after a time of Pharo hardening his own heart God decided to enough was enough and hardend Pharo's heart even more... I shudder to think what would have happend had Moses become Pharo and Moses had hardend his heart twoard God??