The other day while I was browsing through Fisheaters watching the usual confrontations, one poster (an SSPXer) made a great point that has been on my heart the past couple days, especially in light of the theological debates that I've been in.
She said that all of the pointing fingers and calling so-and-so a heretic/schismatic and saying who is and isn't in the Church should not be determined by us sinners, but that what we should really be doing is making sure that we're in a State of Grace (not guilty of any mortal sin) and seek virtue and piety regardless of what Mass we attend and in spite of our views on "being in-communion with Rome."
I was pretty floored and thought to myself, "Wow, I'm not in a State of Grace, and the arguing to seeing with whom I agree and disagree is not going to restore me back to God's friendship." It was quite humbling. Of course her post was ignored by most of the alpha male youngeons who are trying to impress each other... *rolls eyes*
Protestants and non-believers often accuse Roman Catholics (and the Eastern Orthodox if they even know who they are) of going to the priest for forgiveness instead of going to God directly. Sadly, I think a lot of us Catholics do have that mindset, but oh how flawed it is and it is such a trick of Satan to delay our seeking the Grace of God.
We need to be begging the Lord for mercy frequently throughout the day, and definitely before we retire to sleep at night because we never know when the Lord will come for us (First Epistle of St. Paul the Apostle to the Thessalonians, V, 2) and should we be guilty or conscious of even one mortal sin at that time, our souls will be lost for all eternity and we will be confined to the endless woes of Hell.
All mortal sins can be forgiven by making a sincere and devout act of Perfect Contrition (Catechism of the Catholic Church 1452) WITH the firm resolution to receive the Sacrament of Penance ASAP afterwards. If one is truly sorry for his sins, he naturally has the intention of going to Confession if and when he can. Keep in mind the Perfect Contrition is sorrow for sin motivated by the Theological Virtue of Charity, love for God and extreme anguish of the soul at having offended His goodness.
We should try to make these acts frequently throughout the day and not just when we know we're going to Confession.
"If we confess our sins, he is faithful and just, to forgive us our sins, and to cleanse us from all iniquity." --First Epistle of St. John the Evangelist, I, 9)
We can (and should) confess our sins to God at any time if we are truly sorry for our sins and are ready to turn from our evil ways.
Keep in mind that although we have Perfect Contrition and earnestly ask for the forgiveness of God, we may not partake of any of the Sacraments (Penance excepted) until we have received sacramental absolution through the Sacrament of Penance. We MAY NOT receive Holy Communion if we have any mortal sins to confess for which we have not yet received sacramental absolution. This is a Law of the Church. Case closed. But this does not in any way remove our obligation to always ask for God's forgiveness.
Another thing to note is even though we have Perfect Contrition and make a sincere act before the majesty of God, we do not receive the Sanctifying Grace of the Sacrament, and therefore do not receive the Sacramental Grace to help us avoid the sin and it is likely that we may fall again very soon. This is why it is important and necessary to make frequent Confessions (frequent by the Church's standards means at least once a month or more).
If we do not have Perfect Contrition, we may still receive the Sacrament of Penance provided we have at least Imperfect Contrition (or attrition) which means a distaste and disgust for sin because of how evil it is and because we fear not going to Heaven or we fear going to Hell. Perfect Contrition is motivated by love for God, while Imperfect Contrition is motivated by fear of His Judgments. The latter is the minimun necessary to receive the Sacrament of Penance.
Imperfect Contrition will NOT forgive mortal sin even in light of imminent death, so we must get ourselves into the habit of having Perfect Contrition and always pray for the increase in Charity which the Sacraments give.
If we die in a State of Grace, we are promised Eternal Life, although the fires of Purgatory are likely especially if we do not receive sacramental absolution or the Sacrament of Extreme Unction (or Annointing of the Sick).
Please read and pray the Seven Penitential Psalms 6, 31, 37, 50, 101, 129, and 142 (or for the modern Bibles 6, 32, 38, 51, 102, 130, and 143).