Let me start this off by saying that I am not a moderator or a member of staff here. I am, at the time of this writing, a relatively new member. I have no authority here and can not, nor would I, assert these as "rules" for this forum.

What I can do is assure everyone who reads this that if you take it seriously and utilize the information I am providing here, your arguments and points will be taken more seriously and you will likely have a good experience here. I can also assure you that if you don't, your arguments and points will almost certainly become the subject of (arguably) deserved ridicule.

Rest assured that if the things you say get ridiculed, it's because they are ridiculous...It's not personal.

And now, since that is covered, I'm going to start by talking about how one should approach the act of posting a thread in a debate forum.

First and foremost, make sure your starting post (OP/Original Post) is very clear, direct and to the point. Make sure it is formatted and that you use appropriate punctuation.

Walls of text, long, run-on sentences and assertions without evidence will be treated as if you'd taken a bowl of alphabet soup and thrown it at the screen. They will not be taken seriously. Your lack of writing skill will be pointed out. Silly things will be said.

So let's talk a little about formatting: When you make a post, it should go like this:

Greeting

The thing you are asserting

Definitions

Demonstrable evidence for that assertion, including sources and free of logical fallacies.

Demonstrable evidence for that assertion, part 2.

Demonstrable evidence for that assertion, part 3.

Demonstrable evidence for that assertion, part 4.

etc...

Please note that I have placed line breaks between the greeting, the assertion and the various blocks of evidence. This is done so that the readers can easily differentiate between points and different pieces of demonstrable evidence. Furthermore, it is a matter of courtesy to make sure that your post is as easy to read as possible. If you want your post to be taken seriously, you should follow that formatting. If you don't follow it, many people here will refuse to read it, as word-salad, and things will quickly devolve into ridiculousness.

Please also note the structure of the advice I put forth: Definitions and demonstrable evidence for that assertion, including sources and free of logical fallacies. If you're not providing evidence, you're proselytizing. Don't proselytize. If you do, you'll be ridiculed.

This is where the vast majority of theist/deist claims fall short (if not all of them). The providing of definitions and evidence which is sourced and free of logical fallacies. Due to this, I want to spend a little bit of time talking about what evidence is and what logical fallacies are.

First, evidence: A definition.

ev·i·dence
/ˈevədəns/
noun
1.
the available body of facts or information indicating whether a belief or proposition is true or valid.

And now, demonstrable: A definition.

de·mon·stra·ble
/dəˈmänstrəb(ə)l/
adjective
clearly apparent or capable of being logically proved.

And when we put the two together, demonstrable evidence is the available body of facts or information indicating whether a belief or proposition is true or valid, which is clearly apparent or capable of being logically proved.

And let's put this all together in a very simple assertion, with demonstrable evidence:

I assert that on a cloudless day, during daylight hours the sky tends to be blue.

My testing methodology was to go outside, during daylight hours, and look at the sky on 100 cloudless days. On 100 of those 100 days, the cloudless sky was blue.

Note that I included repeatable testing which provides demonstrable evidence of my claim. The cited source would by myself.

Also, please be aware of Sagan's standard: "Extraordinary claims require extraordinary evidence". If you assert that you own a goldfish, very little, if any, evidence will be required to prove that. We know people own goldfish and have done for quite a long time. To believe that you own one is trivial.

If, however, you assert something extraordinary like "there is an invisible, unknowable, omnipotent, omniscient being who exists within space-time and, simultaneously, outside of space-time who created the sun, moon, stars and the entirety of the universe, along with everyone and everything within it", you must be prepared to provide extraordinary evidence for that assertion.

Also, this needs to be said: Feelings are not evidence. Impressions are not evidence. Personal experiences are not evidence. The bible is not evidence. The cosmological argument is not evidence. Anecdotes are not evidence. Stories are not evidence. Telling someone that you believe in god because he speaks directly to you is not evidence. Saying that a supernatural force lifted you out of a swimming pool while you were drowning is not evidence of anything other than a hypoxic hallucination. Learn what evidence is and isn't and provide evidence, not hokum.

I feel it is important to talk about "the burden of proof" here, so I will. Fortunately, this will be short:

The burden of proof is always on the shoulders of the person who is making the claim. If you make an assertion, it is incumbent upon you to provide the evidence for that claim. If someone does not believe that claim, it is not upon them to provide proof against it.

Latin: Onus probandi incumbit ei qui dicit non ei qui negat.
English: The burden of the proof lies upon him who affirms, not him who denies

I also mentioned logical fallacies and I would like to take a moment to talk about those.

First, a definition:

A logical fallacy is an error in reasoning that renders an argument invalid.

This is a short and concise definition and was sourced, here: https://www.thoughtco.com/what-is-logical-fallacy-1691259

Now, I would like to talk about the most common logical fallacies we see in debates on forums:

Argumentum ad ignorantiam. English: argument from ignorance:

Argumentum ad ignorantiam says something is true because it has not yet been proved false. Or, that something is false if it has not yet been proved true. ("God is real because nobody has shown him to be false")

The devine fallacy or argument from personal incredulity:

The divine fallacy is an informal fallacy that often happens when people say something must be the result of superior, divine, alien or supernatural causes because it is unimaginable for it not to be so. Also commonly referred to as "god of the gaps" in which gaps in scientific knowledge are taken to be evidence or proof of God's existence. ("Trees are proof of god. They must be because engineers can't make a tree from nothing and scientists can't explain exactly where they came from")

Argumentum ab auctoritate. English: Argument from authority:

Argumentum ab auctoritate is a form of defeasible argument in which a claimed authority's support is used as evidence for an argument's conclusion. ("[Insert smart/well known person here], believes in god so god must be real")

Argumentum ad populum. English: Argument from popular belief or Argument from popularity:

Argumentum ad populum concludes that a proposition must be true because many or most people believe it, often concisely encapsulated as: "If many believe so, it is so." ("There are over 2 billion christians so god must be real")

Circulus in probando. English: Circular reasoning:

Circulus in probando is a logical fallacy in which the reasoner begins with what they are trying to end with. ("God is real because it says so in the bible and the bible is correct because it's the word of god")

Straw-man Fallacy:

Straw man occurs when someone argues that a person holds a view that is actually not what the other person believes. ("You're an atheist. I can't believe you say people who believe in god are stupid!")

While these are the most common fallacies I can think of being used in forum debates, this list is certainly not exhaustive. Many more logical fallacies exist and most of them get used but, again, these are the most common ones I can think of, off the top of my head. You'll still see false dichotomies, slippery slopes, begging the question, hasty generalizations, tu quoque, post hoc ergo propter hoc, equivocation, etc., but they seem rarer to me.

And, finally, the last thing I would like to address:

When the fight is lost, stop fighting. When you make a claim you can't back up and it's shown that you can't back it up, don't pull stuff out of your butt to try to drag it out. Just take the hit, admit that you can't back it up and watch how much respect you gain.

I'm going to give an example of the type of stuff I've seen, in a rather general sense:

Bob: "The night sky is blue"
Frank: "No it isn't"
B: "Yes it is"
F: "Please show evidence of the night sky being blue"
B: "It's blue right now"
F: "No, it's clearly black"
B: "It was blue last night"
F: "No it wasn't"
B: "Well, it looked blue to me"
F: "How could it have?"
B: "I have a thing with my eyes. Black appears blue to me"
F: "Ok so the sky appeared blue to you but was actually black"
B: "Black is a human construct"
F: "lefuq?"
B: "Since black is a human construct I can interpret it any way I want and I don't need proof that the night sky is blue"
F: "Ok, we're done here"
B: "And how do you know there's even a sky? How do you know anything exists outside your own consciousness?"
F: "I'm going, now"
B: "Geese bark like dogs"
F: "........."
B: "I win"

No. You didn't win. Being a douche doesn't make you win, it makes other people give up on talking sense to you because it's clear you're never going to get it and they are no longer going to waste their time. Stop it. Be an adult. Don't deflect. Don't make the same point over and over again or ask the same question over and over again. Take your lumps when they come and...wait for it...maybe actually learn something in the process. If you believe something that you have no reasonable cause to believe, that is not a reasonable belief. If it is not reasonable, there is no reason to have it.

Don't chicken out with hard solipsism, unfalsifiable crap, double-talk, word salad or using the same tired-ass arguments over and over and over. If you can think of an argument, we've probably heard it. If we've heard it, it has most likely been refuted. If it's been refuted, don't pose it here because we're going to use the same methods of refuting it and it's just a waste of time. Come in with something new.

Ok, I lied. This is my last point:

If you want to argue cosmology, talk to a cosmologist. If you want to argue physics, talk to a physicist. If you want to argue medicine, talk to a doctor. Don't come in here spewing string theory and quantum mechanics as they relate to the pharmaceutical industry's ability or willingness to cure cancer and, by golly, that proves god. If you do, you will be ridiculed.

And I think that's that. Welcome, please enjoy your time and may whatever god you believe in help you if you stray from these modest guidelines and post a bunch of ignorance.

edit: cleaned up a grammatical error.