Thanks Shabir for the debate. I thought it was a positive time with progress made. Here are a few followup comments to consider after watching the debate:
1. Shabir referred to the scholar Bruce Chilton and said that Jesus does not identify himself, in Mark, as the eschatological Son of Man of Daniel 7. However he does because he claims to be the Messiah who sits at God's right hand (Mark 12:35-37) and this is the position of the eschatological Son of Man in Jesus' confession (Mark 14:61-62). Also Mark 10:35-45 is a discussion about ruling in the coming kingdom. We agree that the Son of Man rules this coming kingdom, but notice what Jesus says, in this context, about the Son of Man:
For even the Son of Man did not come to be served, but to serve, and to give his life as a ransom for many. (Mark 10:45)
Therefore Jesus again identifies himself as the eschatological Son of Man.
2. I pointed out that for a God that is only absolute oneness this God becomes a "what" not a "who", is unknowable, and is confused with creation. Shabir said that this was a problem for all monotheistic religions. But this is not the case because the Trinity has both oneness and diversity. Thus the Trinity is "who" by definition and not a "what"; is knowable because the attributes are an expression of distinction and the doctrine of the image of God means some of God's attributes are communicable; and there is no confusion with creation again because of an acknowledged distinction with God.
3. Regarding how three can be in one. I did not plan to explain this in the debate because my focus was to establish that God has both oneness and diversity. I established this, and I hope people realise how significant this is. However, regarding how three can be in one I offer this explanation.
Personal existence is not simple. For the Christian God personally dwells in us by his Spirit. God is present in our thoughts and mind. For the Muslim Allah is closer to us than our jugular vein and our own soul can speak to us (Qur'an 50:16). This shows how personal existence is not simple. Or consider spirit possession. Spirits have a degree of transcendence and a different type of spatial existence to humans. Here one or more spirits indwell one human, that is, there are many in one.
These examples are not presented as illustrations of the Trinity. God is unique. Instead they are meant to show that in both Christianity and Islam how persons exist is not straight forward. Therefore we cannot assume that one being can only have one person. Sometimes there are multiple persons in one being. Here is my booklet on the Steps Towards the Trinity