Something that i don't understand

But of that day and that hour knoweth no man, no, not the angels which are in heaven, neither the Son, but the Father. (Mark 13:32)

I found this verse in some video made by a muslim and he says that if the son doesn't know but the father does that means that the holy trinity is false and so is chrisitanity
I am a christian but i don't know how to answer this question and its making me wonder
(forgive me if i say a ton of wrong stuff english isn't my first language)