First of all, this is a mistake that many (if not most) psychedelic users make...they believe that the drug is God. Regardless of whether or not it can induce a spiritual experience, if it's NEEDED to come in contact with the divine, then it's simply a mask for selfish drug abuse. I'm not here to debate whether they can be used for good or not; what I am saying is that even coming from someone with an open mind about these things, this is heinous. The "you wouldn't understand, you haven't done it" argument is also ridiculous, and an assumption that your mind operates in this addictive bubble like his does. I'm also not here to debate on homosexuality, but here's the deal:
1. He lied. That which is based on lies, thrives on lies. You will find out more and more about him that you do not like or agree with.
2. Your belief structures clearly don't match. I'm not going to say "He's not a Christian so he's wrong; dump him" but I WILL say that your faith is clearly important to you, and you have your convictions that it is truth. When you're as passionate and convinced of something as God, Christ, etc., being intimate with someone who clearly disagrees is going to cause tension, heartache, and looooots of stress. Plus, if you succumb to his wishes, you may find yourself falling from what saved you in the first place.
3. Unfaithful? The biggest killer. Not only is it nearly impossible to repair, it tends to repeat itself.
4. He curses, insults you, claims you don't understand. The more you stay, the more you believe him. He's got this idea that he's the cat, and you're the mouse - and he's got you where he wants you. It's not about you, or even "us"; it's about power.
5. You can talk to a person suffering from deep depression as much as you want, and it can often help, but NOTHING WILL CHANGE until they are determined to change. No matter how hard you try, you do not have the power to change them. It becomes a battle of will - your will for him may be strong, but his will for himself is equally stronger...and it is actually stronger as he governs his own actions. Ultimately, God's will determines reality.
Asking if anyone has stopped psychedelics for the sake of faith will not provide the answers, or guidance, you need....however, I will respond. While psychedelics don't compile the majority of my drug resume, I will speak on drug use in general: I'm not opposed to certain things, but I do not use them for a reason. I have an extensive history with drugs, including the abuse of many prescriptions, ecstasy, cocaine, crack, meth, acid, mushrooms, ketamine, mescaline, and others. I come from a very loving family who watched me destroy myself for years. Granted, I couldn't have done it without them; however, what stopped me was not their talks, or letters, or what have you. What stopped me was multiple hospital visits, depression, and finally realizing that I chose what path to take. This may not be what you want to hear - no one wants to see a loved one suffer. But the more you stick around, the more you cater to his manipulative "needs" and the more comfortable he'll be.
The truth is, in my opinion, if he's going to change, for one he needs to lose you. If it devastates him, it may be the catalyst to him realizing what he's done. If it doesn't bother him in the least, then you certainly deserve better, and he'll burn himself out eventually in other ways.
Also, take caution when dealing with the separation. Many times the "victim" will drop to their knees, cry, beg forgiveness, and of course you (having a tender heart) believe they are changed for good. This generally leads to the same painful situation you were in to begin with.
He lied, he's unfaithful, he has no respect for your beliefs or ethical ideas. Drop the guy. Don't hate him, but stay away.