What you need is not sincerity, but the daring of the gambler.
Not solid ground to stand on, but the dexterity of the swimmer.
"This Is Not a Pipe," painting by René Magritte
Beliefs are not Reality
It's essential to remember that all of these ideas are metaphors. Doctrines, words, concepts, thoughts and pictures all translate, emphasize, reflect, and otherwise point to reality. But no description of reality is the reality it describes. Words and pictures, ideas and doctrines, are not the things they point to. They are distorted indicators, utterly different in kind from what they point to. You can describe a tree in your backyard to me all day long, but until I touch it with my own hands, I can't feel its bark. If description can't communicate the tree-ness of a tree, how much less can words communicate God!
This is important! Challenging ideas are often vital for breaking up entrenched thought patterns and opening the mind. Yet no concept, no matter how inspirational, is that divine reality we seek, anymore than Magritte's pipe is something you can pick up and smoke.
We need to remember that God is the name we use for the Unspeakable. Simply put, the Source of everything is beyond all names. The “Trinity” is a conception of how the Infinite One relates to the phenomenal world of beings, matter, and time, which we call Creation. “The Fall from grace” is another. Other religions have their concepts as well—lila, nirvana, maya. But to latch on to any one of these as “the Truth ” instead of a helpful pointer to truth, is to miss the point entirely! It's like several people pointing to that tree in the backyard and arguing whether the tree has three parts or fifteen parts—or arguing if the leaves are dark green, forest green, or olive.
God cannot be divided. God simply is. The Universe simply is. What is simply is. All our thoughts and concepts divide Is-ness in our minds, and divide our minds from Is-ness.
Awakening is the transition from "religion" with its firm answers, perspectives, and experiences, to realization, the awareness of what IS. Even more important is “Real-ization,” the embodiment of that awareness. The important things in mysticism are not concepts, thoughts, feelings, or even experiences, but the questions and questing for nothing else but this One we call God. Beliefs—in the sense of concepts which must be protected, are not part of Christian mystical life. In this sense, you must not “believe” in God. Instead, just rest in Being. And in being, and being with Being, you rest with God, the Ground of Being. Don't “believe” in the Trinity. Trust the holy and wholly indescribable Reality in whom you “live, move, and have your being”.
The Greek word pisteo is almost always translated “belief” or “faith” in the New Testament. However, it also means trust and is better translated as such. Dare to move from belief to trust.
Slowly, joyfully, lovingly, destroy your concepts and mental images into the burning furnace of just being with the One. Just love what is, seen and unseen. Don't name it. Don't label it. Don't even think about it. Just do what Jesus said: Come as a child.
“Whoever will not receive the kingdom of God like a little child will never enter into it.”