The apostle Paul provides one reason
why we can be convinced that God
exists, even though we cannot see him [he found the God Particle, it blinded him, and now he's writing a paper on it].
Regarding Jehovah, Paul wrote: “His invisible
qualities are clearly seen from the
world’s creation onward, because they
are perceived by the things made, even
his eternal power and Godship.” (Rom.
1:20) How might you help someone who
doubts the existence of God to see the
truthfulness of Paul’s inspired words? [Mind control works, most of the time. That's what I'd use.]
You could consider some of the following
evidence from creation that reveals
our Creator’s power and wisdom [because whatever is in creation proves that it was made by Jehovah as opposed to Zeus, Baal, etc.--he totally signed his name on every piece of DNA, we already cracked the genetic code here at Watchtower and so we know this for a fact, but if you ask for the research papers on it, you'll have a visit from three elders in your near future. So don't ask.].
--sd-7