I see no reason to doubt that this is a form of a Christianity. His beliefs is the logical consequence of someone who believes in the original script of the Bible. When one uses Biblical words to form a belief about earth's age or the evolution of our species and refuse to accept the scientific consensus, why should he choose to ignore the Leviticus 20:13 as he mentions it his sermon?
I went over to see what this passage says, and as I was suspecting, it commands the following:
Leviticus 20:13 ESV - If a man lies with a… | Biblia
13 f If a man lies with a male as with a woman, both of them have committed an abomination; they shall surely be put to death; their blood is upon them.
As is the case with all religions, believers make a wide range of choices regarding which passages accept to the letter and which ones choose to modify by using the rationale that they were written to address only the needs of people in the past and do not apply in modern times.
The fundamentalists who stick to the "fundamentals" and refuse to change their interpretation over time to embrace modern ethical norms are those people who "cling to their religion" (as Obama put it) and become resentful about a world that deviates from their "fundamental" ethics. Such type of resentment does not need a lot to become hate and even actionable hate. Imagine for example this person getting some unfair indeed treatment from say a gay supervisor. I would not be surprised to see such person snap...