Serve God in spirit and in truth, not spirit and in faith. The anchor is truth (and the religious calculus that is closer and closer approximations to truth) not faith. When I was a child, I spoke as a child. Children, teenagers, and adults can drift from the faith of their spiritual childhood, but we cannot drift from learning.

Here is a truth. Humans are social. Humans at some point will need saving. This happens when a teenage life guard saves or watches over others. This happens when an adult's father dies, then the mother dies, and the church is compassionate to care about that person. This happens when fire, flood or other weather conditions causes people to rescue/save others. We could go on but where does it lead? Have faith in Christianity, a religion built on the truth of the human need, physical and spiritual, to be saved.