Question

For this particular situation and for those who doesn't believe, let us assume that souls exists. So how will you convince a non believer about their existence?

Answer 1

To be honest, I can't convince anyone and neither can anyone except the person himself.
There's a quote that sums it up :
"Don't waste your time with explanation, people only hear what they want to" - Paulo Coelho.
Well, I can try to make them believe in it by substituting the concept of 'souls' in an axiom and by glorifying 'souls'.
So, I can try, but I won't cause "Nobody listens to a poor philosopher" - Shah Rukh Khan.

Hope it's helpful.

EmoLord.

Answer 2

You can never really change what someone believes or thinks so you can't convince a non believer to believe in something that they have found impossible.