". . . God gave them over to a depraved mind . . . and although they know the ordinance of God, that those who practice such things are worthy of death, they not only do the same, but also give hearty approval to those who practice them." (Romans 1:28, 32).
It's not hard to preach against homosexuality. God hates it. He singles it out as an egregious abomination (Lev. 20:13). He sends people to hell for practicing it (1 Cor. 6:9; 1 Tim. 1:10) and uses it as a form of judgment to bring morally bankrupt cultures to their end (Rom. 1:20-32). Its divine censure in Scripture is both clear and pervasive. Only the willfully blind think otherwise -- the Anderson Coopers of this world who think being gay is an actual gift from God (gayisagift.blogspot.com). You can cut that darkness with a knife. But what's a little harder to preach is that God puts those who give hearty agreement to this lifestyle in the same category as the people who practice it. Agreeing it's "okay to be gay" is to be guilty by association -- a guilt that marks a person as being under God's wrath.
Two observations and an admonition:
First, those that approve share the same depraved mind as those that practice. They're a set. To encourage is to empower. And the people in this "approval" category are myriad -- from the President of the United States, senators, and doctors, to many of your friends on Facebook who see this as only an "equality" issue. To approve of what they do is to disapprove of what God does. He who is not with God is against Him. Either the degenerate are right or God is right. To be politically correct is to be theologically judged.
Second, those that approve share the same supporting sins as those that practice. No one who is gay is devoid of practicing a form of these sins -- "all unrighteousness, wickedness, greed, evil; full of envy, murder, strife, deceit, malice . . . gossips, slanderers, haters of God, insolent, arrogant, boastful, inventors of evil, disobedient to parents, without understanding, untrustworthy, unloving, unmerciful" (Rom. 1:29-31). Depraved minds produce depraved actions -- be it a tacit admission or a hearty approval. Not everyone in Sodom was a sodomite. But everyone in Sodom died as a Sodomite. God's judgment is the same for both those who practice and for those who agree with the practice.
Lastly, repent from this false tolerance. Lot had to flee Sodom, resign from the city council, and not look back (Gen. 19:9, 17). While we love all sinners and plead for them to flee from God's wrath, to not get in the lifeboat and leave all forms of approval of homosexuality is to sink with the Titanic. Quit calling evil good (Isa. 5:20) -- or even normal. Come out of the "tolerant" closet before you're locked into it forever.