In mathematics, when we deal with infinity we deal with the nature of infinity in such a way that is verifiable. It’d be absurd to demand that we manipulate expressions with explicit knowledge of infinity.
In life, when we deal with God we deal with the nature of God in such a way that God has made verifiable. It’d be absurd to demand that we place our belief in God only when we can obtain explicit knowledge of God. Like infinity, explicit and complete knowledge of God is impossible to obtain.
Note: I don’t think the nature of infinity or the nature of God is any less real than actual infinity or God. Understanding one’s nature allows a small glimpse into what that nature is part of and actually is. Beyond this, I feel like this analogy is too simple and dangerous. Take it for what it is: An analogy.