Infilling of the Holy Spirit

3.3 How to receive forgiveness of sins

1. Decide not to enjoy the fruit of the sin again.
2. Lead a Holy life hereafter
3. Forgive your enemies
4. Make restitution
5. Do fasting prayer
6. Give alms
7. Confess to a priest

1. Decide not to enjoy the fruit of the sin again.
"As a clue to changes of heart four turns of fortune appear, good and evil, life and death; and it is the tongue that continually rules them." -- Sirach 37:17-18

2. Lead a Holy life hereafter
"See, you are well! Sin no more, that nothing worse befall you." -- John 5:14

3. Forgive your enemies
"For if you forgive men their trespasses, your heavenly Father also will forgive you; but if you do not forgive men their trespasses, neither will your Father forgive your trespasses." -- Matthew 6:14-15 

4. Make restitution
"And when Jesus came to the place, he looked up and said to him, "Zacchae′us, make haste and come down; for I must stay at your house today." So he made haste and came down, and received him joyfully. And when they saw it they all murmured, "He has gone in to be the guest of a man who is a sinner." And Zacchae′us stood and said to the Lord, "Behold, Lord, the half of my goods I give to the poor; and if I have defrauded any one of anything, I restore it fourfold." And Jesus said to him, "Today salvation has come to this house, since he also is a son of Abraham. For the Son of man came to seek and to save the lost."" -- Luke 19:5-10

5. Do fasting prayer
 "Jonah began to go into the city, going a day's journey. And he cried, "Yet forty days, and Nin′eveh shall be overthrown!" And the people of Nin′eveh believed God; they proclaimed a fast, and put on sackcloth, from the greatest of them to the least of them. Then tidings reached the king of Nin′eveh, and he arose from his throne, removed his robe, and covered himself with sackcloth, and sat in ashes.  And he made proclamation and published through Nin′eveh, "By the decree of the king and his nobles: Let neither man nor beast, herd nor flock, taste anything; let them not feed, or drink water, but let man and beast be covered with sackcloth, and let them cry mightily to God; yea, let every one turn from his evil way and from the violence which is in his hands. Who knows, God may yet repent and turn from his fierce anger, so that we perish not?" When God saw what they did, how they turned from their evil way, God repented of the evil which he had said he would do to them; and he did not do it." -- Jonah 3:4-10

6. Give alms
"For charity delivers from death and keeps you from entering the darkness; and for all who practice it charity is an excellent offering in the presence of the Most High." -- Tobit 4:10-11 

7. Confess to a priest
CIC 989: All the faithful who have reached the age of discretion are bound faithfully to confess their grave sins at least once a year.

CCCC 305: Each of the faithful who has reached the age of discretion is bound to confess his or her mortal sins always before receiving Holy Communion.

"If you forgive the sins of any, they are forgiven; if you retain the sins of any, they are retained." -- John 20:23

"Therefore confess your sins to one another, and pray for one another, that you may be healed. The prayer of a righteous man has great power in its effects." -- James 5:16 

Non-Catholics may do only six steps to receive forgiveness of sins.