Ringer
Jar of Clay
Prove to me that he does exist and then I won't talk.
Unfortunately, I doubt anything from a Christian perspective would suffice for you. Christians were not commanded to go out onto the ends of the world and give people proof for God's existence. However, they were commanded to spread the gospel message. Why? Maybe because there is truth in the message and when you know truth, you know God.
So Jesus was saying to those Jews who had believed Him, "If you continue in My word, then you are truly disciples of Mine; and you will know the truth, and the truth will make you free."
"Sanctify them by the truth; your word is truth."
If you are just looking for God's existence through evidence, you may come up empty handed. Nature itself is enough evidence for some but for those who require more, I always suggest taking an honest look at the Bible and praying (yes, asking for a leap of faith here) that you are to know truth when presented to you.