There is no good argument against Trinity.
When people usually speak about trinity, they wonder, how can one being be 3 other beings at the same time? how are there 2 Gods? Jesus and his father? and then how are they the same at the same time?
There is a simple debunk of this, so I invite YOU to prove me wrong.
In Christianity, God is omnipotent, which means having unlimited power, authority, or the ability to do anything.
If God is omnipotent, and has unlimited power, can do anything he wants, he can be 2 or more beings at the same time, IF God decided to, he can be 100 different humans, 1000 different animals, and hundred thousand trees or basically ANYTHING you can think of at the same time, so I ask you this, how can 3 NOT be one when we are speaking about an omnipotent being who has ability to do anything?