Acts 17:23-31 NASB1995
[23] For while I was passing through and examining the objects of your worship, I also found an altar with this inscription, ‘TO AN UNKNOWN GOD.’ Therefore what you worship in ignorance, this I proclaim to you. [24] The God who made the world and all things in it, since He is Lord of heaven and earth, does not dwell in temples made with hands; [25] nor is He served by human hands, as though He needed anything, since He Himself gives to all people life and breath and all things; [26] and He made from one man every nation of mankind to live on all the face of the earth, having determined their appointed times and the boundaries of their habitation, [27] that they would seek God, if perhaps they might grope for Him and find Him, though He is not far from each one of us; [28] for in Him we live and move and exist, as even some of your own poets have said, ‘For we also are His children.’ [29] Being then the children of God, we ought not to think that the Divine Nature is like gold or silver or stone, an image formed by the art and thought of man. [30] Therefore having overlooked the times of ignorance, God is now declaring to men that all people everywhere should repent, [31] because He has fixed a day in which He will judge the world in righteousness through a Man whom He has appointed, having furnished proof to all men by raising Him from the dead.” [https://bible.com/bible/100/act.17.23-31.NASB1995]

People say they don’t believe in GOD. They might try to fool themselves into believing that, but we all believe. They will elevate something, or someone, into the place that belongs to the Creator. Just as the Romans had a shrine to the “Unknown God” in their city, we each have a place in our hearts for Him. The question is, who or what replaces the LORD in your heart, or is your heart filled by the Holy Spirit of GOD?

Hebrews 11:1 NASB1995
[1] Now faith is the assurance of things hoped for, the conviction of things not seen. [https://bible.com/bible/100/heb.11.1.NASB1995]