You, like 99% of Christians, don't understand the Catholic teaching on justification. I'm going to break it down for you since so many people can't seem to grasp this.
1. You cannot merit salvation through your own works. Only the sacrifice of Jesus Christ can save people.
2. True faith in Jesus Christ necessarily means following his commands. To have faith and believe in Jesus is to follow Jesus and do as he wills, which means doing good works. Jesus says this explicitly in Matthew 25. Faith is not a state of mind like Protestants believe, faith is action and living your life in obedience to Christ.
>“Then shall He say also unto them on the left hand, ‘Depart from Me, ye cursed, into everlasting fire prepared for the devil and his angels.
>For I hungered, and ye gave Me no meat; I was thirsty, and ye gave Me no drink;
>I was a stranger, and ye took Me not in; naked, and ye clothed Me not; sick and in prison, and ye visited Me not.’
3. Although you cannot merit salvation based on your works you can LOSE salvation based on your works. Jesus tells us if you do not avoid sin then you will be rejected by him and your name erased from the book of life. Thus it is important to avoid sin as much as possible.
>If your right eye causes you to sin, tear it out and throw it away. For it is better that you lose one of your members than that your whole body be thrown into hell.
So no, the Catholic does not say "It doesn't matter", the Catholic is put into a state of mortal sin that can mean if they die without receiving the sacrament of reconciliation (confession) then they will not be saved.