My 101 Reasons for Leaving the Catholic Church:

Assurance 

What is it ?

Martin Luther claimed that "justification by faith alone" is the article upon which the church stands or falls. The gospel, the "good news" of salvation is that the righteousness which a person needs to be reconciled to God does not come through works, but through faith alone. Catholic teaching is that a person is justified not by faith alone, but by faith and baptism; by faith and works; and by faith combined with the Sacraments of the Catholic Church. In the Catholic system, justification is a process that begins at a person's baptism, and does not conclude until death, and for most, PURGATORY. In this process, righteousness is infused into the soul, so that a person can ultimately after death be declared righteous. The Catholic Church teaches that complete sanctification of the sinner is required before a person is fully justified. In contrast, Protestant teaching is that justification is an event whereby a person receives the gift of Christ's righteousness imputed (reckoned) to their account through faith alone, and is thus declared righteous solely on the basis of Christ's righteousness. The justified person is "in Christ." They are deemed a new creation, born again, adopted into the family of God at the point of believing. Good works are deemed to be the fruit, the evidence of the faith which they have in Christ.

At the COUNCIL OF TRENT, the Catholic Church declares in Session 6, Canon 9:

If anyone says that the sinner is justified by faith alone, meaning that nothing else is required to cooperate in order to obtain the grace of justification, and that it is not in any way necessary that he be prepared and disposed by the action of his own will, let him be anathema.

And in Canon 16:  If anyone says that he will for certain, with an absolute and infallible certainty, have that great gift of perseverance even to the end, unless he shall have learned this by a special revelation, let him be anathema. The Catholic Church deems that someone who teaches that Christians should be certain of their salvation solely based on the life and death of Jesus is committing a serious sin and is ultimately cursed to hell.

How did it come about ?

Evangelical assurance is deemed to be the sin of presumption according to Catholic teaching. The Catholic Encyclopedia states that a person is guilty of the sin of presumption who "might look to have his sins forgiven without adequate PENANCE." Faith itself is a gift of God, so that no man can boast. Statement from the Catholic Catechism related to the "new law."

Why it is wrong:

1) ...because faith is defined as assurance, to declare assurance as anathema is to curse true Christians;

2) ...because to add anything as a requirement for justification is to deny the sufficiency of Christ's atoning sacrifice and perfect life. This amounts to unbelief;

3) ...because to place the adherents of the Catholic system under the burden of keeping the "new law" is to keep them from the joyous freedom of knowing Jesus Christ.

Warnings from Scripture:

"Without faith it is impossible to please God" Heb. 11:6