Why would we not admit it 100 % of the time?

ZW:

And when devout Catholics have a spat of honesty or they have been drinking, they admit they believe they can merit eternal life and that proudly.

It is the truth which Scripture teaches. Why would we not admit it 100 % of the time?

1 Timothy 4:16

King James Version (KJV)
¹⁶ Take heed unto thyself, and unto the doctrine; continue in them: for in doing this thou shalt both save thyself, and them that hear thee.

Here's the difference between Catholics and Protestants. The Church teaches us to participate in our own salvation, in obedience to Christ:
Hebrews 5:9

King James Version (KJV)
⁹ And being made perfect, he became the author of eternal salvation unto all them that obey him;

Whereas, Protestants teach people to reject that teaching. And to save themselves according to their faith "alone". Which contradicts Scripture:
James 2:24

King James Version (KJV)
²⁴ Ye see then how that by works a man is justified, and not by faith only.

They claim to judge themselves saved. Which contradicts Scripture:
1 Corinthians 4:3

King James Version (KJV)
³ But with me it is a very small thing that I should be judged of you, or of man's judgment: yea, I judge not mine own self.

They claim to know better than the Church. And that contradicts Scripture:
Ephesians 3:10

King James Version (KJV)
¹⁰ To the intent that now unto the principalities and powers in heavenly places might be known by the church the manifold wisdom of God,

They claim they don't have to obey anyone in the Church. And that contradicts Scripture:
Hebrews 13:17

King James Version (KJV)
¹⁷ Obey them that have the rule over you, and submit yourselves: for they watch for your souls, as they that must give account, that they may do it with joy, and not with grief: for that is unprofitable for you.

They claim that no one can teach them anything about their faith. And that contradicts Scripture:
Hebrews 13:7

King James Version (KJV)
⁷ Remember them which have the rule over you, who have spoken unto you the word of God: whose faith follow, considering the end of their conversation.

In this, they have much in common with the world, because those of the world that believe in an afterlife believe they too save themselves with their works. Ironically, like most Catholics, the worldly also believe they have been good enough to merit eternal life if they died today.

On the contrary. We leave it up to God to judge the merit of our works. It is Protestants who claim they are good enough to be saved whenever they decide. 

Catholicism and the world are shoulder to shoulder in preaching this message from Satan that sinners can begood enough.

On the contrary. And that is easy to prove. Ask a Catholic if they are saved. The answer, "I don't know. God is my Judge." Now ask a Protestant the same question. "Of course!" They will brag and boast! "I have my faith!!! I am saved! Thank God I'm not like the Catholics and all those other people of the world!!!" Now, lets read the Scripture and see who is truly saved:

Luke 18:9-11

King James Version (KJV)
⁹ And he spake this parable unto certain which trusted in themselves that they were righteous, and despised others:
¹⁰ Two men went up into the temple to pray; the one a Pharisee, and the other a publican.
¹¹ The Pharisee stood and prayed thus with himself, God, I thank thee, that I am not as other men are, extortioners, unjust, adulterers, or even as this publican.

That is the Protestant attitude.

Now, Protestants always wonder why we kneel before God in Church. Here's why:¹³ And the publican, standing afar off, would not lift up so much as his eyes unto heaven, but smote upon his breast, saying, God be merciful to me a sinner.
¹⁴ I tell you, this man went down to his house justified rather than the other: for every one that exalteth himself shall be abased; and he that humbleth himself shall be exalted.

Sincerely,

De Maria