What is faith?
Faith is probably the main pillar of religion. It is the answer given by all religious people when asked why they believe something for which there is no logical explanation or proof of truth.
Q Why aren't you worried?
A I have faith God will take care of me.
Q Why do you think you will go to heaven?
A I have faith that God knows that I have faith in him.
The definition of faith that I am using is the belief in anything for which you have no evidence of truth or reality. Almost 100% of all religious belief and dogma is based on faith
The Merriam Webster Dictionary defines faith as
"belief and trust in and loyalty to God
(2) : belief in the traditional doctrines of a religion
b (1) : firm belief in something for which there is no proof clinging to the faith that her missing son would one day return (2) : complete trust
3 : something that is believed especially with strong conviction; especially : a system of religious beliefs the Protestant faith
The Bible describes faith as
(Hebrews 11:1) "Now faith is the substance of things hoped for, and the sign that the things not seen are true"
(Hebrews 11:6) "And without faith it is impossible to please God, because anyone who comes to him must believe that he exists and that he rewards those who earnestly seek him"
As an example: according to the Catholic Diocese of Dallas, Catholics must confess to a priest to have their sins forgiven [by God] because,
That’s the way Jesus set it up on Easter Sunday evening. He told his apostles that just as God the Father had sent him — and God the Father sent him to save us from our sins — so he was sending them.
He breathed on them the power of the Holy Spirit, giving them God’s power to forgive sins, since no one can forgive sins but God alone. He told them that whatever sins they forgive are forgiven and whatever sins they retain are retained (Jn 20:21-23; Mk 2:7).
Since the apostles were unable to read minds, the only way that they would know which to forgive and which to retain is if people told them their sins. Jesus thus established the essential structure of the sacrament of confession. Just as he uses priests to give us his Body and Blood at Mass so he uses them to give us His mercy in Penance.
I ask how do you know that God will forgive your sins if you do that?
I ask how do you know that Jesus said that?
I ask how do you know that if Jesus said that he was correct?
The answer to these questions is always the same. I have faith.
Wouldn't you like to know if this is true?
Most people do not want to know whether their religions beliefs are true. Faith gives a feeling of security and comfort. I as an atheist do not believe in God or religion because I have never seen any evidence that would convince me that it is true. My personal preference is best explained as follows.
I'm going to paraphrase an eminent atheist author, speaker, debater and talk show host, Matt Dillahunty. To the best of my recollection he puts it like this: "I want to believe as many true things and as few false things as possible."