The following can be found here:
http://www.godandscience.org/apologetics/notseegod.html
God Has Not Revealed Himself to Me, So He Must Not Exist
Is God's lack of direct revelation to humans a good proof that He does not exist?
A teacher is using the "scientific method" to teach the class about evolution...
TEACHER: Tommy do you see the tree outside?
TOMMY: Yes.
TEACHER: Tommy, do you see the grass outside?
TOMMY: Yes.
TEACHER: Go outside and look up and see if you can see the sky.
TOMMY: Okay. (He returned a few minutes later) Yes, I saw the sky.
TEACHER: Did you see God?
TOMMY: No.
TEACHER: That's my point. We can't see God because he isn't there. He doesn't exist.
A little girl spoke up and wanted to ask the boy some questions. The teacher agreed and the little girl questioned the boy.
LITTLE GIRL: Tommy, do you see the tree outside?
TOMMY: Yes.
LITTLE GIRL: Tommy do you see the grass outside?
TOMMY: Yessssss (getting tired of the questions this time).
LITTLE GIRL: Did you see the sky?
TOMMY: Yessssss.
LITTLE GIRL: Tommy, do you see the teacher?
TOMMY: Yes
LITTLE GIRL: Do you see the teacher's brain?
TOMMY: No.
LITTLE GIRL: Then according to what we were taught today in school, she must not have one!
The above joke is a good lesson in the problem of trying to prove the existence of God using the scientific tools available to us. A Creator God, if He exists, must, by definition, exist beyond the limits of the universe in order to have created it. The laws of physics tell us that we cannot make measurements beyond the limits of this universe. Therefore, scientists can conclusively determine that we cannot ever detect God using any of our instruments.
However, God is not restricted to our limitations and could choose to reveal part of Himself to us. God could not reveal His entirety to us without causing major problems in our universe. The sudden appearance of dimensions and matter(?) from outside the universe would destroy anything in the vicinity and maybe even destroy the entire universe. This is why the Bible says that nobody can see God and live.1 However, God could reveal His nature by communicating with humans and sending an incarnated version of Himself. This is exactly what Christianity claims - that God gave messages to humans (through the prophets) and sent an incarnation of Himself (His Son), who took on the form of a human2 in order to interact with humans directly.
Although you cannot see God directly in this life (but you will see Him in the next), you can experience Him through your spirit. This is the claim and promise3 of Christianity that accounts for its popularity. When you accept Jesus Christ as Lord and Savior,4 you enter into a relationship with Him through the Holy Spirit. The indwelling of the Holy Spirit, which you will directly experience when you come to faith, confirms both the existence and the power of God to the believer. It is through this relationship that we can enter into the joy of the Lord and experience the fullness of the Christian life.5
If you are not a Christian, you will not believe what I just told you. I know, because when I was an agnostic for 33 years, I did not believe that you could have a relationship with God. Since 1988 I have been experiencing the joy of the fellowship of the Lord and I want the same for you. Don't wait! Get your questions answered and come to faith based upon the facts, and enter into the joy that cannot be found through anything else in this world.
Well, its your choice. Do you see your brain?