The very same grace that saves the liar, cheat, fraud, murder, or adulterer... saves the homosexual. It is our need for grace that brings us to Him. If we justify our sin, we're essentially saying that we don't need a Savior.
1 John 1:9-10 King James Version (KJV)
9 If we confess our sins, he is faithful and just to forgive us our sins, and to cleanse us from all unrighteousness.
10 If we say that we have not sinned, we make him a liar, and his word is not in us.
Frankly, affirming the sin cuts them off from the opportunity to experience the grace of God that saves us all.