There is a truth called the law of gravity. It existed long before it was formulated as a scientific law. Objects will not stop falling to earth if someone refuses to believe in gravity. Gravity does not care if anyone believes it. It just is.
There is one self-evident truth greater than all the others, and that is God:
"For since the creation of the world God’s invisible qualities—his eternal power and divine nature—have been clearly seen, being understood from what has been made, so that men are without excuse" (Romans 1:20).
"The fool says in his heart, 'There is no God.' They are corrupt, and their ways are vile; there is no one who does good" (Psalm 53:1).
Believing in God does not make Him God, but not believing in Him has dire consequences.
"The Father loves the Son and has placed everything in his hands. Whoever believes in the Son has eternal life, but whoever rejects the Son will not see life, for God’s wrath remains on him" (John 3:35-36).
The truth of God’s actions is both self-evident and revealed in His Word. There are two great acts of God—the creation and redemption. The God of creation is self-evident to the created. Redemption is a historical act that needs to be proclaimed:
"For, 'Everyone who calls on the name of the Lord will be saved.' How, then, can they call on the one they have not believed in? And how can they believe in the one of whom they have not heard? And how can they hear without someone preaching to them? And how can they preach unless they are sent? As it is written, 'How beautiful are the feet of those who bring good news!'” (Romans 10:13-15).
"Consequently, faith comes from hearing the message, and the message is heard through the word of Christ" (Romans 10:17).