Yes the Mark of haShatan is DO WHAT THOU WILT. Whatever feels good, whatever you want, just explain away all reason and truth and righteousness as nothing to be ashamed of. Sin is the mark when you give in to sin. We all sin but to GIVE IN to it is The Mark.

Consequently, the Mark of YaHuWaH is to do Righteousness. What is righteousness? It is that which provides Eternal Salvation by Practice and from the giving sacrifice of our Savior by our Almighty.

Mat 19:16-18 On the way, one came to Him and said, "Great teacher, what good thing shall I do that I may have eternal life?"
He said to him, "Why do you call Me ‘Great’? No one is ‘Great’ but One, that is, YaHuWaH Almighty of All Creation. If you want to have Eternal Life, keep The Covenant Words (Commandments)."
He said to him, "But which ones?" YaHuW said, “Why have you never studied The Covenant?