The word "contrition" comes from the Latin word "CONTRITIO" - "I crush".
Without a soft heart, the healing graces of God flow off like water on a rock. Sin makes us selfish and hardens our hearts. But a contrite heart absorbs the graces of God like a sponge absorbs water.
I am contrite by being truly sorry for my sins. I am truly sorry for my sins by acknowledging my grievous offenses against my loving God and against my neighbor and having a deep heartfelt regret for the sins and a firm purpose of amendment not to sin again. I grow in confession especially by understanding what MY SINS have done to JESUS, especially as manifested in His Agony in the Garden, Scourging at the Pillar, Crowning with Thorns, and Carrying of the Cross, and Crucifixion and Death.
By being contrite we can do what is proper to us who are creatures wounded by sin: We cannot fix ourselves, but we can hate what is evil in us - that is, our sin. We so dispose ourselves to let God do what is proper to Him: To FORGIVE!
By heartfelt contrition, we seek our justice not "in ourselves" but in Jesus Christ. Jesus wants us to TRUST in Him. Jesus absolutely requested that the signature of the Divine Mercy image be "JESUS I TRUST IN YOU". When we look at the Divine Mercy Image we see the Picture of His infinite Mercy, Goodness, and Love; when we read the signature "JESUS I TRUST IN YOU" with our hearts we respond as we ought.
Our contrition is PERFECT when we are sorry because of what we have done to Jesus because of our sins. It is IMPERFECT when we are sorry because of what our sins do to us: disgrace, temporal and possibly eternal punishment.
Catholics are most blessed because the Sacrament of Confession perfects imperfect contrition such that even mortal sins will be forgiven. Otherwise, mortal sins can be forgiven only by having perfect contrition.
But having perfect contrition is hard especially when in the state of mortal sin. Why? Because sin causes us to love ourselves before God. Only God knows if our contrition is perfect or not. Avoid presumption and go to Confession!
If a Catholic is not in the state of grace, his perfect contrition includes to do what Jesus tells us to do thorough His Church: To go to confession! So no one should go to Holy Communion if they are aware of having an unconfessed mortal sin. Going to Holy Communion when aware of unconfessed mortal sin is sacrilege - the worst of all sins.
If our contrition is perfect, we don't need any punishment! Why? Because there is no more need of punishment since the soul already loves God above all! So continually increase your sorrow for sins, perfect your contrition, and go to confession often. Pray for the souls in Purgatory. Then when you die you can hope to go straight to heaven since there is not any need to be further cleansed in Purgatory!
For Meditation on Contrition:
(1) From the "Conversation of the Merciful God with a Sinful Soul", Diary of St. Faustina, #1485
Jesus: My mercy is greater than your sins and those of the entire world. Who can measure the extent of my goodness? For you I descended from heaven to earth; for you I allowed myself to be nailed to the cross; for you I let my Sacred Heart be pierced with a lance, thus opening wide the source of mercy for you. Come, then, with trust to draw graces from this fountain. I never reject a contrite heart. Your misery has disappeared in the depths of My mercy. Do not argue with Me about your wretchedness. You will give me pleasure if you hand over to me all your troubles and griefs. I shall heap upon you the treasures of My grace.
(2) From the "Conversation of the Merciful God with a Despairing Soul", Diary of St. Faustina, #1486
Jesus: My child, all your sins have not wounded My Heart as painfully as your present lack of trust does — that after so many efforts of My love and mercy, you should still doubt My goodness.
Part 2: Confession
I confess my sins to Jesus directly through the priest. Why "directly" through the priest? Because Jesus has ordained that man such that the priest is His instrument for forgiving sins: It is really Christ who forgives the sins.
When Jesus forgives us through His representative the priest, there is no less grace than if he was to forgive us 2000 years ago when He walked the face of the earth. Just as there is no less grace to be present at the Consecration at Holy Mass than to be on your knees before Christ when He died on the Cross.
It is fitting that Jesus instituted the Sacrament of Penance: "He breathed on them; and he said to them: Receive ye the Holy Ghost. Whose sins you shall forgive, they are forgiven them; and whose sins you shall retain, they are retained" (Jn 20:22-23). We offend God and His Church when we sin; we fittingly confess our sins to Jesus through His ordained representative. Sin increases our pride so that we "live a lie"; confession humbles us so as to perfect our contrition. The soul that is dead cannot revive itself but needs a new infusion of life. Jesus revives the soul, shipwrecked by mortal sin even after baptism, by the Sacrament of Confession.
We KNOW that Jesus forgives us when we confess our sins. We just have to confess our sins without hiding them.
We confess mortal sins by type and number. If we "hold back" a mortal sin, then we are not making a good confession. The confession itself becomes a sin; the soul does not even have the necessary imperfect contrition when it knowingly refuses to confess a sin.
If we forgot a sin, our confession is still good. But we need to confess the mortal sin later and as soon as we can.
It would be impossible to confess each venial sin, imperfection, and fault by type and number - there would be too many. Instead of really becoming holy by the grace of Christ, we would become preoccupied with our own defects and could actually fall into the trap of trying to perfect ourselves instead of disposing ourselves to be perfected by Christ.
Instead, confess CONTRITELY and CONCISELY your dominant venial sins and faults, knowing full well that we cannot fully express in a brief confession the depths of our misery. Thus we see the need for the MOST BLESSED SACRAMENT - the Holy Eucharist. In Holy Communion, Jesus perfects us and burns away our faults and sins by His divine love. Frequent confession - even for venial sins and faults - is a very powerful preparation for the worthy reception of the Sacrament of Love - the Holy Eucharist.
Remember: all souls are prideful and selfish. Confessing such broad generalities afford little in confession. Rather, confess HOW I am prideful and selfish, without going into unnecessary detail. (e.g., "I talked back to my parents several times and did not take their correction well.") That is the proper material to take to Confession.
Part 3: Absolution
Jesus forgives the soul directly when the priest says the words of absolution.
Do you believe in Jesus? Then believe in His will and ability to forgive the soul with the words of absolution that He speaks through the lips of His ordained ministers. Jesus was crucified because HE FORGAVE SINS - and only God can forgive sins. But His claim to forgive sins is not blasphemy but is the Truth because He - the Second Person of the Trinity - is GOD and Man.
It suffices to repeat our Lord's exhortation to St. Faustina: (Diary of St. Faustina, 1448)
Write, speak of My mercy. Tell souls where they are to look for solace; that is, in the Tribunal of Mercy [the Sacrament of Reconciliation] There the greatest miracles take place [and] are incessantly repeated. To avail oneself of this miracle, it is not necessary to go on a great pilgrimage or to carry out some external ceremony; it suffices to come with faith to the feet of My representative and to reveal to him one's misery, and the miracle of Divine Mercy will be fully demonstrated. Were a soul like a decaying corpse so that from a human standpoint, there would be no [hope of] restoration and everything would already be lost, it is not so with God. The miracle of Divine Mercy restores that soul in full. Oh, how miserable are those who do not take advantage of the miracle of God's mercy! You will call out in vain, but it will be too late.
Part 4: Penance
We should fulfill our penance promptly and with devotion.
Does our penance take away our sins? NO! Jesus takes away our sins by shedding His Blood on the Cross. Our penance is our fitting "two bits" which is a way of expressing our sorrow and gratitude.
Our penance usually consist of a short prayer. After Jesus forgives us in absolution, we are already 'working for Him' in the work of salvation; we are 'back on track' working for His glory and for the salvation of souls - even if it is only by saying a simple prayer!
Consider the great model penitent in St. Peter who denied Jesus three times. Did He do penance? Yes, he was sorry and forgiven by Christ. Did he have his own type of "penance" similar to that of confession? Yes, three times Jesus asked him, "Simon, son of John, lovest thou me?" Peter was "hurt" as penance is sometimes hard: "Peter was grieved, because he had said to him the third time: Lovest thou me? And he said to him: Lord, thou knowest all things: thou knowest that I love thee."
Peter is "back on track". His dignity is restored and winning souls for God.
Glorify God in His Mercy in the great Sacrament of Penance! That is not man's plan; but God's plan to revive life in the soul!