Most people would really like to ‘prove’ that their version of God exists. So far, no one has managed it.
There are 4 types of proof which can be attempted. First is ‘scientific proof’, where a repeatable ‘experiment’ has reliable results which proves the premise. God(s) are supernatural, by definition, so do not follow the laws of science we are constrained by. This type of proof has never been successfully used. Will it ever be? I doubt it.
Next is ‘logical proof’. This is where you start with provable assumptions and use valid logical arguments to prove your viewpoint. This has been used a lot – invalidly. In every single case I’ve run into, either one or more assumptions were not provable or even valid, or at least one step of the logical argument was invalid. Perhaps the most obvious (and annoying) instance of this is the ever popular “The Bible is the Word of God, because it says so in the Bible”. Sorry, the rules of logic do not permit the premise to prove itself. Another is the attempt to just prove that God exists. “Every design has a designer, The Earth has a design. Thus the Earth has a designer”. In this case, the logic is valid, but let’s look at the assumptions. “Every design has a designer” is inherently true, so no problem there. “The Earth has a design”; now this one is problematical. It sure does seem like it has a design, the way everything fits together in just the right way, but ‘seem’ does not guarantee ‘is’.
Then there is ‘personal experience’. This is where you know something to be true because you personally experienced it. This is a very powerful proof to the person with the experience, but much less so to everyone else. Some may accept it as true because they trust the person claiming the experience; others likely will not if they don’t know or trust the person.
Finally, there is ‘legal proof’, where something is so ‘beyond reasonable doubt’. As you can tell by a brief glance at the history of our legal system, this is just an indication, not proof.
What it comes down to, is ‘faith’; ‘belief’. And this may very well be by design. In the Bible, it is made very clear that belief is very important to God. Why? I have no idea, but it does seem that God set things up so that it would be impossible to ‘prove’ Him; you would HAVE to have belief to interact with him.
Before I was saved, I was amused or annoyed at the attempts made to ‘prove’ anything to do with God, but I’ll tell you, once they used invalid logic, unproven assumptions or just stated things as facts which they could not back up, I tended to discount everything they said.
How then can you share God with others? Forget scientific or logical ‘proof’, it can just make you look silly. Don’t state your beliefs or theories as facts; state them as YOUR beliefs or theories. If the people know you well, personal experience may be accepted, but don’t rely on this alone. Showing that your view of God COULD be true or even better, is LIKELY to be true, is a first step on the path to showing someone the light. Perhaps the most important thing you can do is to show, by your everyday actions, your relationship to God. Nothing will ruin your attempts to share God faster or more completely than having your actions be at odds with your words.