Q. The Biblical translations that I’m aware of all capitalize pronouns referring to God in the New Testament no matter if the Father, Son, or Holy Spirit is in context, except for 2 Thes. 2:6-7. The restrainer, I do believe, is the Holy Spirit but why isn’t the pronoun “he” capitalized?
A. I think it’s because in the opinion of many 2 Thes. 2:6-7 is not necessarily about the Holy Spirit. Other opinions include human government and the rule of law; spreading the gospel; the binding of Satan; the providence of God; the Jewish state; the Church; and the Archangel Michael.
I prefer the Holy Spirit because the influence for good He projects through the Church has historically restrained the growth of evil in the world. In addition, there’s a precedent for His withdrawal before a world wide judgment. God also withdrew the Holy Spirit before the Great Flood (Genesis 6:3).