head The point is that you don't understand all of God, in one go. Understanding grows and develops.
Some you might get from church, some reading the Bible, some you learn through reflecting on experiences, some from study around the subject, all lead by the Holy Ghost.
However all along the way are people, who are fallible. No one, apart from Christ, has all the answers. So we immerse ourselves, in what we know of Him.
Sitting in church, once a week, saying a few prayers, singing a few hymns, listening to a sermon, joining in with the ritual, is not all there is to being a Christian (although these things can strengthen Faith).