In mankind's history there can be found natural theology which is generally characterized as the attempt to establish religious truths by rational argument and without reliance upon alleged revelations. Newt to it we may find lots of name-Christians trying to proof God exist but for them Jesus being God, others can see that their idea of God being Eternal, Immaterial, Transcending space, The Creator and Designer of the universe, Omnipotent, Omniscient, The unique greatest possible Being, does not fit at all their Jesus-god. Many people putting 2 and 2 together decide then wrongly because those qualities not fitting Jesus, he is not being able to be God but then there than also not being a Supreme God.
Being conscious that nothing can be the cause of itself we have to look for That What is responsible to have the beginning of something and What gives life into it. Not finding anything which could create itself from nothing we should come to see Who is behind the beginning of everything. Ultimately we should conclude that there has to be a prime Beginning, or Something or Some One Who Causes, and that Causer we call the Creator is God.
We look at a visible or invisible God, Who is the Being Itself Which created heaven and earth and gave life into beings which got to be.