The way to know God is life and living life. "In him we live and move and have our being." Acts 17:28. However there is a massive problem that there is no empirical evidence for God's existence and no philosophical proof of God's existence works. Many theologians have stated that there is also a paradox - God is utterly transcendent and thus unknowable to human minds (like the Hindu Brahman) but at the same time utterly immanent and closer than one's own thought. God is the great mystery of life.
All books (including the bible) are only the thoughts of humans as they try to articulate their experience of this paradoxical transcendent / immanent God. Jews see the holy spirit not as another person in a duality or trinity of the One God Yahweh but as the shekinah glory of God experienced by humans.
Spirit = mind = soul = psyche. They are all the same. One is supposed to use one's mind to know God. The mind experiences rational thought as well as emotion and intuition. Do not despise using all of your mind in the process of finding God.
You may use a book as a reference of how others have found God but they are all fallible and all have errors as well as truth. A short list of possible texts to explore:
- bible
- Qur'an
- Tanakh
- Great Hymn to the Aten
- Egyptian Book of the Dead
- Tibetan Book of the Dead
- Vedas, Sutras and Upanishads
- Tao Te Ching
Or it may be that you explore God through oral tradition such as the Australian Aboriginal Dreamtime.
Find your own path. Others can share their journey with you but your own authentic journey is the one that counts for you.