By faith we understand that the universe was created by the word of God, so that what is seen was not made out of things that are visible.
How can we know how and why we’re here? I don’t mean what happened, we can postulate and theorize about the “big bang” but how did that which went “bang” come into being, and why was it there? It is by faith we trust in God. Science does not even ask such questions, that is the realm of Theology and Philosophy, but it is only answered by revelation. The Bible tells us, and we have faith.