As homosexuality becomes increasingly popular in our culture, LGBT advocates are getting more vocal about it, whereas Christians, and Conservatives in general, are getting increasingly fearful. "There's nothing wrong with it, so shut up you bigot". Well, first of all, no, I'm not going to shut up. I have as much of a right to express my views as you do. But I think we both know the reason you don't want me speaking. It's because I speak about things I've thought of, you speak about things you refuse to think of.
To show this, let's ask one simple question: What gives you the right to say there's nothing wrong with homosexuality? It turns out, those in favor of homosexuality never have a solid defence of it. They can make a range of excuses, but they can't ever say anything stronger than "it's my opinion".
But here's the problem with that: You're human. That means, in the grand scheme of things, your opinions are insignificant. Your opinions were formed with you, they will die with you. Furthermore, there is literally nothing special about you when compared to the other nearly 8 billion people on Earth. What makes your opinion more significant than another person's?
The thing about truth is it transcends opinion. If it was your opinion that 9 + 10 = 21, you'd be wrong, but not because of the opinion of better mathematicians. As it stands, your opinion is probably that 9 + 10 = 19, at which point you're right, but not because it's your opinion. Rather, it's your opinion because it's true.
Thus, in order to solidify your opinions on homosexuality, you must appeal to something beyond yourself. But when it comes to moral issues, only one thing can help you. The problem is, if you think homosexuality is ok, that one thing is actually against you. See, just as one needs a government in order to call something legal/illegal, one needs a god to declare something moral/immoral. Without a god, we're just things doing things. You might think the things we do are good/evil, but without God, there's no way to justify these assessments.
This is what justifies me, as a Christian, in my assessment that homosexuality is immoral: I'm appealing to a source beyond myself. The same source that says it is wrong for me to, for example, steal something, regardless of how much I want it, also says I cannot justify returning to my own homosexual lifestyle.
See, as humans, we're limited in more than just authority. Even when we seek justice, we don't always succeed. We can't always catch thieves, and even when we do, we may be too harsh, or too lenient. But God, being omnipotent, is capable of executing perfect justice, which in the end He will do. When the time comes for us to leave this world, every thought, every word, and every deed, will be taken into account, and He will deal out the appropriate penalty for every wrongdoing. And He has the right to go along with His abilities, for He created us. He created our bodies, including the sexual functions. He created the world in which we live. He created the processes by which we obtain food and water. Even when we think we are independent, we can be proven wrong by one question: Did you invent the seed?
So, God created and sustains us. God invented sex. By what logic does God not get to say "right, if I'm going to continue blessing you, you're going to enjoy sex only in the context within which I designed it"? Why shouldn't God get to say "you committed sexual immorality, therefore I'm going to deal out the appropriate punishment"? What gives you any right to demand He grants you complete independence? If God is not your foundation, you have no foundation!
Of course, this concept does not apply exclusively to homosexuality. I used it as my example only because it is so prominent and emotional in our culture. But we do live in a relativistic culture in which we tend to say "do what feels good". Well to that I say one man's meat is another man's poison. What feels good to you, someone else may consider an abomination. God may consider an abomination. But the difference is, God is not our equal. He is far greater than us in everything. Greater in knowledge, greater in authority, greater in power, and greater in love.
Being greater in knowledge allows Him to see what you don't. You may think you have it all figured out, so you get to just live your own way, but you don't. I know things about homosexuality now that make it much easier to reject my past. Imagine what He knows. He knows how best to sustain our societies, how best to prosper us, how to give us long and happy lives. If we just obeyed Him, everything would be wonderful. We'd have Heaven on Earth until we moved from Earth to Heaven.
His authority gives Him the absolute right to dictate how we should live our lives. He would even have the right to command chaos if He wanted. If God wanted to tell a man to go on a murder spree, raping every last one of his victims as they bleed out, He would have that right (though thankfully, it's not in His nature). He has the absolute right to judge us, knowing every sin we've ever committed, and the most appropriate way to deal with it.
His power means this is inevitable. There is literally nothing we can do about this. We can't fight Him, and it's foolish to think otherwise. You would sooner extinguish the sun with a water pistol than overcome the Lord.
But greatest of all of His attributes is His love. See, contrary to the narrative, God loves gay people. His word tells us He takes no pleasure in the death of the wicked (Ezekiel 18:23-32; 33:11), that He wants no one to perish (2 Peter 3:9), and that He wants all people to be saved and come to the knowledge of the truth (1 Timothy 2:4). God may well send sinners to Hell, but He has absolutely no desire to do so. Therefore, He came up with a solution. Long before the foundation of the world, it was ordained that the Son of God would enter creation as a man, live a perfect life, and die a sinner's death. Though innocent, He died as if He was guilty, so that we, who are all guilty regardless of our specific stance on sexuality, may be saved. The one condition is faith. That is, we must repent of (change our attitude towards) sin, confess Jesus as Lord (i.e. our Creator and King), and believe in our hearts He was raised from the dead. If we do that, we will be saved from the fires of Hell, and instead inherit an eternal place in His Kingdom.