We know God by what He did and does and will do for us, and by how He loves us, and by the whole host of evidence that exists, physically, mentally, emotionally, historically, spiritually and philisophically for those things.
We don’t NEED to know how He does what He does, or is what He is, any more than we need to know the exact process by which the money that bought us a generous and loving gift was created from paper.
There are some things that are simply bigger than our ability to fully understand as we are now. That’s okay. The how is much, much less important in this case than the Why.
If you can understand that, you’ll be closer to something that will never fail you or leave you behind, no matter how bad everything else may be.