Because he keeps avoiding the use of personal pronouns for God. "God shows God's whatever" gets old after a while. About 27-29 minutes into the video, he finally lapsed and used his/him about 3 times. It was a relief.
The English language uses personal pronouns in a number of ways, including the avoidance of too frequent use of antecedent nouns. English finds it a fault to over-use a noun. The repetition grates. This is especially true when the personal pronoun would come in an unstressed position, where "his" (for instance) would be barely heard as "'z."
English is, at bottom, still tied to the rhythms we find in OE alliterative meter. The flow of stresses in a sentence is a basic part of English as it is spoken or declaimed (this includes preaching and lecturing). To use "God's" constantly introduces a stressed element into the flow of the sentence that breaks it up. Which means it's fine to use "God's" when you want the extra stress in the line, or to make a distinction (God's, not somebody else's), but it's a fault to put one there that makes your speech clunky. It's like dropping anvils for your audience to stub their toes on.
This kind of picky speech pattern where one avoids using masculine pronouns to refer to God is a particularly irritating form of political correctness. It may show forth your sensitivity to some things, but it doesn't do much to demonstrate your mastery of the English language. I'm surprised to find an Asburian hung up on it.