Mohammed Hijab claims Christians think Old Testament Jews believed in the Holy Trinity. Hijab then says this isn't true, which is correct and no Christians have ever claimed that Jews believe in the Trinity. He then uses this as an argument against the Holy Trinity, suggesting that if God did not reveal himself to be One God in Three Persons to the Jewish people back then, then he isn't. Someone needs to explain to Mohammed the idea of God revealing things over time. He also did not reveal himself to the Jews straight away. Also, his own logic would be problematic for Islam, given that it was not 'revealed' to Muhammad until the 7th century.