A Brief Explanation of the Trinity - Doesn’t the doctrine of the Trinity entail contradictions?
Mysteries are not contradictions. Here are two examples of contradictions: there is one God and there is not one God, or God is three persons and God is not three persons. But the claim that the one God exists in three persons who share the same divine essence in perfect unity does not entail a contradiction (Grudem, p. 256).
The Trinity ultimately is a mystery, but it is revealed in scripture, so all Bible-educated and Bible-believing Christians believe in it, even though they may not understand it fully.