The Bible says that we must accept by faith the fact that God exists: "And without faith it is impossible to please God, because anyone who comes to Him must believe that He exists and that He rewards those who earnestly seek Him" (Hebrews 11:6). If God so desired, He could simply appear and prove to the whole world that He exists. But if He did that, there would be no need for faith. "Then Jesus told him, ‘Because you have seen me, you have believed; blessed are those who have not seen and yet have believed'" (John 20:29).
That does not mean, however, that there is no evidence of God's existence. The Bible states, "The heavens declare the glory of God; the skies proclaim the work of His hands. Day after day they pour forth speech; night after night they display knowledge. There is no speech or language where their voice is not heard. Their voice goes out into all the earth, their words to the ends of the world" (Psalm 19:1-4). Looking at the stars, understanding the vastness of the universe, observing the wonders of nature, seeing the beauty of a sunset-all of these things point to a Creator God. If these were not enough, there is also evidence of God in our own hearts. Ecclesiastes 3:11 tells us, "...He has also set eternity in the hearts of men." Deep within us is the recognition that there is something beyond this life and someone beyond this world. We can deny this knowledge intellectually, but God's presence in us and all around us is still obvious. Despite this, the Bible warns that some will still deny God's existence: "The fool says in his heart, ‘There is no God'" (Psalm 14:1). Since the vast majority of people throughout history, in all cultures, in all civilizations, and on all continents believe in the existence of some kind of God, there must be something (or someone) causing this belief.