I often hear that people don't convert to the Faith simply because of bad will.

But what exactly is "bad will"? Where is the origin of the expression and the Church teaching on it?

Finally, how can you help a bad willed person?

I often hear that people don't convert to the Faith simply because of bad will.

But what exactly is "bad will"? Where is the origin of the expression and the Church teaching on it?

Finally, how can you help a bad willed person?

Bad will means that they are choosing the wrong thing on purpose using their Free Will.

Catholic doctrine says that God gave us Free Will, which means we are free to choose good or evil. We can make our own free choices, without coercion.

If you place a plate of meat in front of a hungry dog or cat, the animals will eat the food 1000 out of 1000 times, because they have no free agency. They are programmed with instincts by God. These instincts fully determine their behavior in a given situation.

But man could stare at that plate of food, even while starving hungry, and decide with his will to make a sacrifice.

Those who deny Free Will believe that if you could know everything about a man (all of his background, upbringing, strengths/weaknesses, education, habits, knowledge of human psychology, etc.) that you could predict his behavior -- that he would never surprise you. The Catholic Church holds this position to be heretical.

For one thing, the devil has all of those advantages (he knows everything about us, and he is a master of human psychology), and yet he can't force us to commit the first venial sin. We choose to commit every sin that we commit.

It's called "the mystery of iniquity" why some people choose God, and others choose the devil -- especially since the devil has already lost. Why some choose eternity, while others place all their hopes of happiness in this fleeting world. How could some people be so stupid? The mystery of iniquity.

Remember that every single man or woman in Hell is there by their own fault. They made the decision at some point to "give up" on God and doing the right thing, and embraced evil. If this were not true, then God would not be fair. But such a suggestion would be blasphemy.

When someone is openly looking for the truth, but they HAPPEN TO BE IN ERROR, we say this person has "good will". He's not maliciously choosing evil or the wrong path.

But when someone knows better, has full Catholic training, has a solid Traditional Catholic upbringing, perhaps even 6 years of Seminary training with holy and intelligent Catholic professors, yet he openly tries to surrender his organization to the Modernists in Rome, then you have someone of bad will. Someone who is maliciously choosing self over God, a.k.a. pursuing evil.

what exactly is "bad will"? Where is the origin of the expression and the Church teaching on it?

Bad will is called malice (malitia).
cf. Summa Theologica I-II q. 76, e.g.:

Man like any other being has naturally an appetite for the good; and so if his appetite incline away to evil, this is due to corruption or disorder in some one of the principles of man: for it is thus that sin occurs in the actions of natural things. Now the principles of human acts are the intellect, and the appetite, both rational (i.e. the will) and sensitive. Therefore even as sin occurs in human acts, sometimes through a defect of the intellect, as when anyone sins through ignorance, and sometimes through a defect in the sensitive appetite, as when anyone sins through passion, so too does it occur through a defect consisting in a disorder of the will. Now the will is out of order when it loves more the lesser good. Again, the consequence of loving a thing less is that one chooses to suffer some hurt in its regard, in order to obtain a good that one loves more: as when a man, even knowingly, suffers the loss of a limb, that he may save his life which he loves more. Accordingly when an inordinate will loves some temporal good, e.g. riches or pleasure, more than the order of reason or Divine law, or Divine charity, or some such thing, it follows that it is willing to suffer the loss of some spiritual good, so that it may obtain possession of some temporal good. Now evil is merely the privation of some good; and so a man wishes knowingly a spiritual evil, which is evil simply, whereby he is deprived of a spiritual good, in order to possess a temporal good: wherefore he is said to sin through certain malice or on purpose, because he chooses evil knowingly.