There is a lot that you and I know about God just by looking at the creation. The Bible is very clear that God speaks to you through the Bible, and not only through the Bible. In Paul's letter to the Romans, it says that everything that can be known about God, and the Godhead (including Jesus and the Holy Ghost), is known to you and I through the things that He has created. When you look at the creation around you, God speaks to you through your conscience. That's why you know right from wrong. That is why you know that you are helpless to save yourself from your own sin. Though your conscience can lose its sensitivity when you continually ignore it, it is still there, and God speaks to you through it. Only a fool would say in his heart there is no God.  (some caveats about hearing God's Voice)

God has made Himself very obvious in the things that He has created. And God knows that you know. He knows your thoughts even better than you do. You get confused with rationalized supposition and trying to hide your own sinful nature from others and from yourself. God is never confused. He is not impressed with phony arguments or human logic. It's between you and God, not anything else.

You can't fool God. No one can. He knows. Many an Atheist, Materialist, and Naturalist has tried in vain to convince God and self that they believe that God does not exist, but God does not believe in Atheists: Romans 1:20
2 Peter 3
Psalm 94:9,10

God loves you and created you to fellowship with Him. Revelation 3:20 This is your destiny. In fact, your mind will not work correctly without the Holy Anointing from the Holy Spirit of God. It is, after all, the Spirit of Love, because God is Love.

Illustration of God's Obviousness: Stare At This Picture For 60 Seconds. A Giraffe Will Appear.