Not everyone. People do so for various reasons, some because they don’t want anyone to tell them what the truth is, some are scandalized by what they see others do, some because of pride. Many forget that the Church is the remedy for sin, and while we should all be stiving for sainthood, we are not all there yet. However many do leave the Church because they are ignorant of what the Church really teaches, and fall easy prey to false charges against the Church. Ignorant is not a dirty word, it is just the reality that some people are either uneducated about some of the basics of their faith or the history of the Church let alone the world in general. I would not be offended if someone told me I was ignorant of Astrophysics. I’d agree that I’m ignorant of it.

Now the Church distinguishes between vincible and invincible ignorance. Vincible ignorance is when someone remains uneducated about the faith through their own laziness. Invincible ignorance is when someone is either so prejudiced against the faith, or lives in a place where the Gospel is not readily available and they cannot hear the truth.

Many Protestants say Aborigines in Africa, or a Muslim in Iraq will go to hell because he never accepted Christ. The Catholic Church teaches that if someone never had the chance to hear the truth, and accept it, God will judge him based on natural law, and what he knew. The Church still believes that the graces that lead to his salvation are won for us by Jesus Sacrifice on the Cross, and the Graces that are applied to us by the actions of Church, in the sacraments and good works, and prayers of the faithful. Some theologians think that at the judgement of the soul of the pagan or Muslim or Jew, he will be informed that Jesus is the second person of the Trinity, and all that he needs to know to make a decision will be revealed to him, however that is not an official teaching of the Church but theological speculation. All we know is that we need to trust in God’s mercy.