Human beings, almost universally, have an inner yearning for more than our physical existence — a cry for meaning, purpose, and/or life beyond the grave. Through out the recorded history of mankind this yearning has given rise to the idea of a force, an intelligence, and/or a Creator beyond, yet the origin of, the physical world.
There are four main ways that people have responded to the concept of God: rationalism, religion, rebellion, or revelation.
Rationalism is the attempt to explain or understand God with the human mind. From Aristotle to apologists to atheists, there have been many arguments made to either prove or disprove God. But the fact is, the concept of a transcendent God outside of the natural world, can never be proven or disproved by human reason.
Religion is ritual, tradition, and customs about God that are taught by organizations, institutions, and/or society. The human race is inundated with religion of various types. Through out human history, the majority of people have accepted (at least nominally) the religion of their upbringing and/or culture. Thus, religion tends toward a geographical approach to God — outwardly agreeing and/or adhering to what the institutions and people around you say they believe.
Rebellion is giving mental ascent to a religion or to the concept of God, yet ignoring the implications of that ascent. Rebellion acknowledges the existence of God but makes behavior choices based on personal desires and self-interest rather than on concern to obey God and/or the teachings of religion.
Revelation is the direct human experience of God. It is personal encounter and relationship with God. From Paul of Tarsus to AA/NA, untold millions of people have been touched and transformed by contact with a Higher Power. The personal accounts of people who were changed by meeting God are amazing.