Dealing With Sin As If It Is Physical And Not Spiritual Is Unbiblical

To think that there is such a thing as "mental illness" or  homosexuality is in part due to DNA or just physical things, necessarily means one doesn't need to deal with such as spiritual issues, but rather deal with these matters according to the flesh. Yet what God says is this:

2Co 10:3 For though we walk in the flesh, we do not war according to the flesh,
2Co 10:4 for the weapons of our warfare are not of the flesh, but divinely powerful for the destruction of fortresses.
2Co 10:5 We are destroying speculations and every lofty thing raised up against the knowledge of God, and we are taking every thought captive to the obedience of Christ,

Romans 1 and Phil. 4 says these are indeed spiritual issues. 

Col 2:8  See to it that no one takes you captive by philosophy and empty deceit, according to human tradition, according to the elemental spirits of the world, and not according to Christ.

Heb 4:12  For the word of God is living and active and sharper than any two-edged sword, and piercing as far as the division of soul and spirit, of both joints and marrow, and able to judge the thoughts and intentions of the heart. 

Heb 4:13  And there is no creature hidden from His sight, but all things are open and laid bare to the eyes of Him with whom we have to do. 

Eph 4:17  So this I say, and affirm together with the Lord, that you walk no longer just as the Gentiles also walk, in the futility of their mind, 18  being darkened in their understanding, excluded from the life of God because of the ignorance that is in them, because of the hardness of their heart;