Are you assuming that all gay men and lesbians profess to be Christian? What you posted was written to the church at Corinth and by inclusion in the canon to use, however we as Christians do not have the right to judge those outside the Body of Christ as Paul wrote in chapter 5 of the same epistle:
1 Corinthians 5:9-13
9 I wrote you in my letter not to associate with immoral people; 10 I did not at all mean with the immoral people of this world, or with the covetous and swindlers, or with idolaters; for then you would have to go out of the world. 11 But actually, I wrote to you not to associate with any so-called brother if he should be an immoral person, or covetous, or an idolater, or a reviler, or a drunkard, or a swindler-- not even to eat with such a one. 12 For what have I to do with judging outsiders? Do you not judge those who are within the church? 13 But those who are outside, God judges. Remove the wicked man from among yourselves.
NAS