I was asked to comment on this video. He is advocating for the ancient heresy of Marcionism which decrees that the God of the Old Testament is a different God than the God of the the New Testament. Marcion rejected the Old Testament and even some of the New Testament. Marcionism was one of the earliest major “heresies” within the early, ancient Church. This video and this article and other video explain Marcionism and effectively refute it. You can read about Marcionism here. Athanasius, in response to Marcionism, recommended that the Church approve the 27 books which comprise the Christian New Testament. You can find a wealth of material on Marcionism on the web.