I think that fundamentalist evangelical Christianity has its fullest expression in atheism because of its godless nature. There are many reasons for this, but the root of all the problems (at least that I can think of) are rooted in the fundamentalists ruthless, brutal, and mindless commitment to the literal interpretation of Scripture (or what they think is a literal interpretation).
So with respect to ethics, it doesn't matter how insane a practice is, who it harms, or how stupid it is, if it adheres to the perceived literal interpretation of Scripture, then they will do it. That is Godless - no attention or fear of God with respect to the commandment to love (many other commands notwithstanding). It is Godless to ignore the needs and nature of ourselves and our fellow human beings because God created us in his image. So yes, homosexuals are created in the image of God.
As for its full expression in atheism:
Fundamentalist evangelicals believe that the bible is God's inerrant and infallible word. So basically the Bible is completely perfect.
1) On the one hand, just about all the teachings of Jesus may as well be toilet paper because evangelicals never tire of completely disregarding them
2) More importantly, an evangelical who sees that their literal interpretation is incorrect has to resort to atheism because God would no longer be the perfect God that they worshiped.
This is why fundamentalist beliefs are inherently Godless. They think that the Bible is perfect from a perfect God, but they treat the Bible with the greatest contempt and when they wake up from this pipe dream they have to deny Christ.
What a shame.