How do I make my athiest friend repent?

You can't because he can't take your silly dogma seriously when you cannot even spell "atheist" properly :)

Prove to him that god exists. "Prove" means in the scientific method way, with lots of tests, experiments, and theoretical background.

The only thing he needs to "repent" is having you as a friend.

* atheist.

Repent for what?

Inside-man is the source. He is the living evidence for the existence of God. Tell him that all human beings are living in a miraculous era of God. This is a temporary miracle of God.

You need to repent, for harass your supposed ' friend ' like you seem to do it.

By doing something that no theists has ever done, give a "good" reason as to why you believe this is necessary. By the time your atheist friend is done blowing your mind with better reasoning, you will need to repent. Of course that is only if you truly listen, most Christians are irrational and never really listen.

You don't. That is a work of the Holy Spirit.

Invite him to belief in GOD ,the Lord of all the worlds.

You can't make anyone do anything. It's witchcraft to try to control other people. Even God doesn't do that. God has given all of us a free will, so you are not permitted to be a bully and try to control other people about anything. You can explain the gospel and show them what they missing, but the decision is theirs and theirs alone. Once they have heard the truth they are responsible to act upon it. If they don't that's their decision.

Live and let live.