Select your faith, construct yourself out of your freedom. The foundational certainty is our own existence. We can infer from our existence and its characteristics that God exists, and through that the rest of the world. Beings with a language experience a mediated reality, so certainty is impossible and doubt is always present. Darwin can be accused of beastalism.
Humans are also species beings.
There are few absolutes, which again reinforces the practicality of life. Morality itself has been built into our biology. This will be the coming of human liberation. On this naturalistic view, the existence of a soul has little if any place. There is little need for religion either.