Why should you believe something rather than knowing it for certain by having evidence ?

There are very few things that any person can assert to know for certain, even with evidence. Science cannot even be done without adopting certain beliefs that are not known for certain 'by having evidence'.

It isn't that Christians don't have evidence for what they believe, it's just that the evidence that convinces them that God is real and that Christ is their Saviour is an internal regeneration which the Holy Spirit works in them individually. It's not empirical evidence that would convince an unbeliever, but rather it's a personal experience which is more real and convincing than any external empirical evidence. So Christians believe in God without physically seeing Him but they don't blindly believe in Him, but rather are convinced by God Himself of the truths of Christianity.

Knowledge is a subset of belief. If you know something, you already believe it.

Evidence never brings certainty.

Beliefs are not a choice. People will form beliefs based on the information they have encountered, and how they interpret it.

a. you don't know NEARLY as much as you think you do. You have not done the experiments seen the data first hand ....people told you this stuff......and you believed it. AKA Faith

b. To think that you are capable of comprehending all that is, and ever was...in your little noggin....is prideful foolishness

Bottom Line, God is bigger than you.....but you can know Him...if you can just get over yourself

Religious faith is belief without reason to be defended against all reason.

There are any number of reasons why people choose to adhere to this "philosophy" so any rationale is as good as another when reason has been cast aside.

believing it is true is having evidence and its certain

if Atheists believe in facts then how does nothing make itself into a universe

and then, the unintelligent self created matter

accidentally created everything including life?

You shouldn't. The reasons religion encourages people to do so are obvious enough- it's how they stay in business; and they ARE businesses, no more, no less.

Can you prove love, empathy, compassion?

Your post lcks basic logic

At least the meaning.