To be honest, physical contact with a Satanist would make me very uncomfortable. But that probably has more to do with my own hang ups.
I would even shake hands with a satanist. We are to love our enemies
Oh my gosh I am scandalized. Yashua would not shake hands with a satanist. Oh my gosh oh my gosh oh my gosh...
Well, they are the children of God too, who by our example, could come to Christ.
This reminds me of a time I went to Barnes and Noble with some friends that we know. They came into the store and I started to explain why I never shop at Barnes and Noble. I took them to the esoteric/occult book section and started to explain that I do not want to support a business that would patronage books that directly teach the occult.
Anyway I was showing them and pointing out several books, then I picked up a copy of Anton Levey's "satanic bible". I said, "look they even carry the satanic bible". Several people gasped and one full grown adult woman started freaking out that I even touched it!
I was like "um, it's paper made from the same trees that any other book is made from, including the bible". "It's not going to infect me or send some kind of demon into me because I picked it up". I proceeded "I completely object and disagree with the satanic theology, and believe that it poisons the soul, but a simple book isn't going to suddenly shoot some kind of demonic force into me".
Shaking hands is the same way. They aren't going to zap you with a demon or evil. Even if they wanted to or did some kind of funky spell, its not going to work.
With that said, if somebody is a satanist, and is polite, and conducts themselves in a respectful manner towards others, I have absolutely no problem shaking their hand or even carrying on a conversation with them. I don't agree with their theology or religious views. That doesn't mean that they are going to cast the undead soul possess spell and have hells gates burst forth from your chest, and even if they did, it doesn't work.
Don't fear evil, as evil stands on the authority of nothing. Fear God, and your own sins, because God has the authority. As an Orthodox Christian you'll hear many times in prayers (from Matthew 6:13) "For THINE is the kingdom, and the POWER, and the GLORY, forever and ever.
Satan no longer has power outside of temptation or allowing yourself to become possessed. We know this after Job.