In one of the recent comments someone brought up that it’s apparently a contradiction to say that belief in God is rational, yet also say that God is beyond knowledge and beyond reason. In fact, I’ve dealt with this topic before.
Yet, there’s no reason to assume that “God is incomprehensible/a mystery” is somehow mutually exclusive to, “Believing in God is rational.”
To say that God is incomprehensible or that God is a mystery is pointing to God’s ontology; since we are finite and He is infinite, it necessarily follows that we cannot understand Him. Thus, His ontology (should it be said that God has an ontology) is beyond our own, which places necessary limits on our epistemology. This is not to say, however, that we can’t have knowledge of His existence or know the plausibility of His existence.
While we may not understand God, we can point to some evidence where God is plausible, or we can point to logical proofs to show that God necessarily exists. But all of this has to do with our knowledge of His existence, not with His existence proper. When dealing with His existence proper, rather than our knowledge of His existence, we conclude in mystery because He is greater, therefore mystery is a necessary conclusion.
One can think of the universe and how it is a mystery to us because it is greater than us. Yet we can know it exists and we can know certain things about the universe. We do not see the mystery (and our lack of knowledge) as contradictory to our belief that the universe exists; we do not say it is irrational to believe the universe exists just because we see it ultimately as a mystery. So it is with God.