Destiny and Choices

It’s a thing to wonder that every religion has this concept of justifying act violence. In Hinduism Krishna said that we are supposed to our duty and not care about the results(in a situation of a war), in Islam its the concept of jihad, of which I cant comment much since I haven't studied it on my own but from my limited knowledge I can tell that the concept had importance when the small Muslim community in its infancy was threatened by some irrational people long ago and reflects that it was used for self defense and I'm sure Christianity also has some element similar to these .
So does it mean that all the gurus, the prophets and saints of religion had intentions of making their own religion great, knowing that other religions also existed or is it our interpretations that have distorted their teachings. Would prophet Mohamed have any problem with existence of Krishna or did Jesus have any problem with existence of the prophet. It’s really foolish to think that those great enlightened people would even have disagreement with each other imagining they meet each other. So where does this conflict come from, it’s obvious that it’s only our narrow minded approach to their teachings that has resulted in this situation. And these situations I believe, exist only to make us realise this very point. Unless every human being understands this, it is likely going to continue. The fastest way to get to this understanding is to accept this situation and then only take action accordingly.