Martin believed some things that most Protestants would disagree with today, such as Mary being sinless. He was, after all, catholic before he became convinced that the church was corrupt. He didn't want to start a new church, he was trying to reform the existing one, but it didn't happen.

May St. Francis De Sales and all those holy men and women which defended the one, holy, Catholic, and apostolic church during the turbulent time following the erroneous “reformation” pray for us, and through their intercession obtain the graces necessary to call all of our Protestant seperated brethren home to the only church founded by Christ Himself and which offers Himself fully to us in the presence of the Sacrament of the Eucharist, whose magisterium is guided by the Holy Spirit, and which honors (not worships) Mary as Queen of Heaven and Earth! The true Christian faith is, has, and always will be Catholic Veni, Sancte Spiritus!

Maybe a state of Grace needs to be maintained?

Wouldn't such a condition make us under the law?

The Rich Young Man.
16 Now someone approached him and said, “Teacher, what good must I do to gain eternal life?”
17 He answered him, “Why do you ask me about the good? There is only One who is good.* If you wish to enter into life, keep the commandments.”
18 He asked him, “Which ones?” And Jesus replied, “ ‘You shall not kill; you shall not commit adultery; you shall not steal; you shall not bear false witness;
19 honor your father and your mother’; and ‘you shall love your neighbor as yourself.’”

From Matthew 19:

As I read it, that parable suggest you can't serve two Gods. Money being that other "god" of the rich young man's heart.

Yes, it says that, but it also explicitly says to keep the commandments as a condition for eternal life, does it not?

Yes it does but Jesus was speaking to a Jewish fellow who was under the law. Under the law ,keeping the commandments would have been necessary for righteousness. Under the new covenant the blood of Jesus is sufficient for righteousness.

I don't buy it. Jesus didn't say to keep the entire Law of Moses; he explicitly said to keep the commandments, and then specifically listed them. Indeed, earlier in this same chapter, Jesus expressed strong disagreement with the Law of Moses regarding divorce. Jesus didn't qualify any of this by saying it only applies to Jews.

Maybe a state of Grace needs to be maintained?
Wouldn't such a condition make us under the law?