I am really sorry you are struggling with your son. Teenagers can be a challenge. If it is any consolation, remember that this is normal and to be expected. I know that doesn’t make it any easier.
I am a little surprised at some of the posts here that suggest you “tighten the screws”, so to speak. The reality is that once a kid is 16, you really have little to no control over them. I am sure your son probably looks more like a man than he does a little boy.
You can certainly take his phone away from him. And as you stated, he will just go get another. You can put a block on your home internet, but as soon as he walks out of the house he has access to whatever he wants to search for. You can tell him he isn’t allowed to have sex. He can choose to have it while he is away from home. You see how this is.
What you want to do, rather than control at this stage in his life, is positively influence him and the choices he makes. Influencing takes a lot of creativity, patience, and love. It is difficult sometimes. You need to figure out how to “sell” your values in a way that he is going to “buy” them. All of this, without blinking. If he sees you blink, it is pretty much over (not to put any stress on you. LOL)
With all of that said, it is certainly within your right to have boundaries. It is your house, and your rules apply. You control your boundaries, but you don’t really control your son. I think it is always a good thing to work together with a teenager to establish boundaries together. Perhaps he swears around you to get a rise out of you because he is tired of feeling you are trying to convince him of your religious beliefs. If you negotiate with him that you will stop doing that, perhaps you can lead him to a place of being willing to agree he won’t swear in the house. I have seen it over and over again: When a parent lets go of thinking of their older teenager as a child, it is amazing what the two of them can accomplish together.
The best advice I can offer is to accept that your son is not you, and you are not him. You are going to have differences. Sometimes big differences. He may not accept your value system. You certainly can’t force him to believe what you want him to believe.
I realize many here will say this is the wrong approach, but I have seen it work. The teen grows into adulthood with confidence in his/her abilities to respect boundaries and to expect the same in return from those they have relationships with. It is an important thing to learn.