The problem with being good is that you think that's enough, but it's not enough to be good.  Jesus Christ looked at the scribes and Pharisees, who were good, pleasant and respectable people, and he told his disciples, "Do you see them?  They must be better than they are. “In other words, his kindness was not enough.

If you think being good is enough, you mean you're not good enough. 

The problem with being good is that you put the car in front of the mules.  When we see holy people like Mother Teresa, we can realize that she does good things.  Feed the hungry and rescue babies from garbage dumps.  Then we felt inspired and decided to be good too.  So, we volunteer in a soup kitchen and take care of helping the needy. All that is right and fine, but we forget that before mother Teresa went out to the streets spent an hour in contemplative prayer.  She was so much more than good.  She was a Saint.

Her kindness and compassion were of a different order than mere human virtue.  When we prioritize being good instead of being saints, we are replacing sanctification-the process by which God makes us saints from the inside out by a mere human virtue.  The problem with mere human virtue is that it is a purely human virtue.  It doesn't alter our interior.  "Putting on a cowboy hat doesn't mean you're a Texan..."  Just for doing good doesn't mean that you have become the image of Jesus Christ.

The other problem of being good (and being just good) is that in this way we prove that the argument of the atheists is correct.  Atheists like to observe that it is not necessary to be a Christian and go to church to be good.  They're not wrong, by the way.  There are silly people.  When we, as Catholics, highlight good deeds and boast of what we do to feed the hungry and clothe the naked, they conclude that the most important thing about Christianity is to help the poor.  But are they stupid?  If we were the ones who told you that this is the most important thing... We were the ones who kind of sudden turn priorities.  They are not fooling, but they are well prepared because they came to that conclusion from what we told them.  They believe that for Christians the most important thing is to feed the poor and thus come to the conclusion that they do not need to go to church to do so.

And then we wonder why no one attends mass anymore...

The idea that being good is sufficient is the most persistent and pernicious heresy that exists within Catholicism. The ghost of Pelagio still rounds in our sacred precincts and we need to hear over and over again that we should not be just good, we should be better and not only better, but the best.

The church calls it "the universal Call to Holiness", which means that each one of us is called first and foremost to be saints. To be saints is not to be extremely pious, sanctimonious and devout, but to be who God pretends to be. Through prayer, sacrifice, and devotion we come closer to God and the more we approach him the more we will look like the one we worship. This is the main task of the Christian and while we carry out that task, we are impelled to do the good works that characterize our call.