Thousands of people, many with genius IQ'a, have debated this issue, ships. Let's define a few terms if that's okay. When I studied physics, philosophy, religion, and psychology, we used these terms. Theist is a person who feels he can PROVE God exists. An atheist feels he can prove that God does NOT exist. An agnostic feels neither side can prove its belief SO FAR. But an agnostic leaves the door open. Now if this is okay, let's look at a few things.
I believe, and this is my degree in Psych speaking, that you violate the very concepts you are discussing. If an angel from God appeared, you say. How would anyone prove it was an angel? Even if you said "well, it's what we Christians think angels are or have seen them to be in the past" you still cannot prove it. It might be another type of creature that roams this planet. It could be an alien. It could be either of them with a sense of humor.
I want you to know I do not defend atheists. I feel their position to be untenable. How can anyone say God does not or cannot exist when he has not even left this planet? Do you people from either side realize how large this universe is? How many dimensions it might have? How time, space, and atomic behavior affect your senses and even your brains? Are you aware that there is more to the "how we got here" argument than just creation vs. evolution? Could there be a third method that produced what you THINK you observe today? What if there were a third or FOURTH method, but no one, including myself, can even imagine it due to the limitations of our minds?
Just because we have the intelligent or imagination to ask certain questions, it does NOT follow that we have the IQ to understand the answers. We could be in a jar on the shelf of some Martian laboratory for all you know. This might sound like I've watched too many Outer Limits episodes, but the fourth and last dimension isn't necessarily TIME and then that's the end of it. Many now question Einstein's theories and some now are exploring the string theory and others. Can you conceive of space being curved? Can you explain why time slow down the faster you travel through space?
What happens if you pass the speed of light? Many said you would turn into energy (and die). But if we never exceed the speed of light, how will we ever get anywhere in this galaxy? Do these angels of yours travel at the "speed of thought" as the poet states? What are they made of?
E=mc2 had a meaning for Einstein. Many also said matter cannot be created nor destroyed, only changed in shape or form. That's how matter becomes energy in an atomic explosion. If God is pure energy, who or what made Him? An old argument, but no one has yet to provide an answer that satisfies logic. "He's always been here"? How? Why wait for billions of years to make Jesus. To play chess with for billions more years, then say "hey, let's have some fun and make a universe"? I don't think so.
If you study infinity, positive infinity and negative infinity are supposed to be equal. Whatever number you name (n, n+1, etc.) as a positive, then a negative of the same number can be defined. In easy terms, we can imagine living forever and God living forever with us. It's like seeing a light go on or be on already and just picturing it never going out. But it's far more difficult to imagine that same light as having ALWAYS been on and asking this God "yesterday?" YES, the day before, yes, etc. That's what God would have had to be. Can you explain how something can ALWAYS HAVE EXISTED? Then can you prove it?? I doubt it.
The last point is psychology. No one is immune to preconceived or needed at the time beliefs. Most of us were rabid non-believers, then JW's, just as rabid believers, then many left and became more rabid non-believers. We saw no new evidence in the universe, what changed was what we chose to view and how we chose to view it. It happened to me so I'm not placing myself above you.
To conclude, I will give one million dollars cash to anyone who can prove in a proper scientific manner that God exists. I will never have to award that money in the next several million years. Humans don't have the technology to explore enough of the universe to say with certainty what is or is NOT out there. And we'll leave LSD and other things out of this, but if you want a really good argument, try telling someone who is tripping that the telephone poles are NOT swaying in the wind on a calm day.
Good luck.