Why is EVERY religion out there so confident that it, alone, is the RIGHT religion?

Because everyone who blindly adheres to them throws out their mind and divorces themselves from reality.

No religion "out there" is the "right one". This is because religion is man-made and humans are subjugated to making errors. Spirituality is another issue though. The differences are between the two that religion is based on "doing this" or "doing that" (external practises and efforts) , to gain God's approval and acceptance. Spirituality is internally motivated and God already accepts you not on something you have did or are doing but because God loves you. It is based in relationship and defines who you are. Religion tells you that you are a mistake; whereas, Spirituality tells you that you make mistakes. In other words, religion makes you a human "doing" and Spirituality makes you a human "being". This is exactly why religion squabbles over who is right or the "right one", like in my "soap" washes whiter than your soap. Religion is poison to Spirituality.

Because every body sins and every body can be tempted to sin. That's why we are supposed to read the Word of God. Preaching from the Word, teaching from the Word, and learning from the Word and the Word only. Not from interpretation of it, but by studying it. A lot of religions take what they want out of the Word and base there whole religion on certain things in it. We are supposed to follow God's whole Word; not just some of it.

Many religions speak of them having the one true faith like smart guy up there. I think that is what the asker was asking lol.

Don't forget that along with this, they also do not believe automatically any science that disagrees with their religion, until they apologize for it 400 years later.

Not EVERY religion believes that. The Buddha taught that there are many paths to enlightenment, and that we each must find our own way. I have found wisdom in the teachings of a great many of the world's religions, and when I find truth, I acknowledge it, no matter where I found it.

Do you realize that God has never picked a 'right religion' ? The faiths do it and of course they always pick themselves. Religion is a very competitive business.

I would hope that the person believes his religion is the true one, otherwise, WHY GO?

But is your religion the true one according to the bible? Now that is a question everyone should ask, Paul spoke of one faith and God has an acceptable way to worship him.

People trust what they are familiar with (their religion) more than what they are unfamilair with (the religion of others) and well this is a vicious cycle that is almost inevitable.

It is human nature. Just like you probably think your philosophy is correct.

People rely on their beliefs. They find security in them. And they don't want to be wrong.