He would have to raise to life several of my dead friends that died in tragic circumstances (suicide, murder, cancer). I would then have to consider my fallibility.

I would need, at the very least, the slightest credible, verifiable evidence of some sort of deity.
basically, I am unconvinced of extraordinary contentions by mere anecdotes and fallacies, as are most people normally, unless it's a conveniently unfalsifiable, emotionally satisfying myth that they were indoctrinated with before being old enough to think critically.

While I tend to err to the scientific, materialist side of things like most people on here, I'll be generous and give God an easy way out: Pull a fully grown dancing gorilla directly out of Trump's a-hole on live television, and I'll be in the first row pew at the early service on Sunday. My offer has no expiration date.

Do you mean as a specific entity? An anthropomorphic being? My mind just cannot comprehend such a thing - I rejected that when I became atheist. So, if such a being came to earth, I would be doubting my sanity and heading for some help.

Just think of all the ways that God, if real, could immediately and irrefutably prove its own existence. All sorts of miracles might happen. Manifestations. Immediate simultaneous subtle shifts in the neurochemistry of seven billion people to cause them to all believe in the same way.

The Apocalypse -- not some stretched interpretation of current events, I'm talking a literal horseman galloping all over the earth, leaving plague or famine in his wake, or a beast with the number 666 tattooed on its forehead emerging from the bowels of the earth being accepted by all of the nations of the world as their king.

If you want a sample miracle that would convince me, I'll offer: "amputated limb regrows after prayer for same."

Yet despite all of this, and despite the fact that for an omnipotent, omniscient deity doing any of these things would be by definition easy, none of this has ever happened and we all know that none of it ever will.

Verifiable proof.

Excellent question! I am not sure how I would be able to differentiate between an actual deity and some superhuman alien being that was trying to convince me it was a deity. I have thought about this in the past: maybe an actual deity can surprise me by coming up with an answer to a question that no alien, no matter how superbly intelligent, would be able to answer. Back when I was a creationist and ID advocate, I read in an essay from William Demski which suggested a way to distinguish between a divine being and a merely superhuman one: ask a question whose answer takes more information and resources to answer than available in the known universe. An answer to a question that no supercomputer can come up with, no matter how advanced. I don't know if Demski was right about this but this is the best that I have been able to come up with.

Seeing is believing would help.

For him to appear in front of me, make Steven Hawking able to walk and function like everyone else, heal all the people with disease and give plentiful harvests and access to clean water to those who do not need it.

Go back in time and have education removed from me after a certain point. Re believe? I don't know.

i would believe an entity is godlike if it had full control over time, energy, and matter. This would include the ability to travel across the universe instantly, reshape the universe without limits, take me into the past or future and alter events. It would also include making me or anyone immortal including the dead.

Seeing God with my own two eyes would make me believe.

A God is the only thing that could make me believe in God. I would like to say empirical evidence, but I really don't know. Frankly I am unconcerned about it. If God is all knowing, God would know what it would take to convince me. If a God exists and fails to convince me of its existence than it must be as unconcerned about it as I am.

He would have to show up in front of billions of people all at once. He would also have to answer questions and have proof that he is correct. Also show supernatural powers.

Scientific proof. I believe in the sun, the moon, the planets and asteroids because there is enough proof for me.

Winning the lottery may help but then I never ask god because it is pointless.

A religion that doesn't practice hating on and ostracising non-believers. So far the Islamic and christians are on the same page when it comes to this. Being at work has proved this to me.

Absolutely Undeniable, Empirically Tried, Tested and tangible, factual Evidence tested, examined, re-tested, re-examined by a panel of its Peers is the ONLY way I would even vaguely consider believing that ANY God/s/Goddesses exist or have ever existed.

Doubt it!!!!

Tangible evidence ... valid proof.

A person encounter and perhaps seeing someones prayers being answered. Prayer and the lack of response is one reason I am a "skeptic"

I'm convinced that it's impossible to prove the existence of god. Only god itself could possibly make me abandon logic and reason and believe in god. So far, I'm unconvinced.

PROOF! Doesn't hafta be anything really spectacular, just something that i would recognize as a sign!

I don't know.

But a God would. So if it wants me to believe, it knows what to do.

Actual proof! Scientific, verifiable, reproducible, tangible physical PROOF. God actually showing up would be a nice start. .But he will have to PROVE that he did it,