Imagine for a moment what happens when we die... We are shown a movie of our entire life. In the movie, we see all the things we did, and we also notice a number of blanks in between some parts of the movie. When asked why there seem to be such blanks in the movie of our life, Jesus tells us that these were the times when we sinned and asked for God’s mercy through the Sacrament of Reconciliation. When we asked for God's mercy and forgiveness, our sins are forgiven, and He does not remember them anymore. Such sins are finito, gone with the wind, so to speak.
In today's gospel, Jesus says, "Everyone who speaks a word against the Son of Man will be forgiven, but the one who blasphemes against the Holy Spirit will not be forgiven." What is this sin that could not be forgiven? The Holy Spirit is the Advocate who is constantly beckoning us to "Turn back to our loving God." And so the unforgivable sin is our attitude when we say, "There is no hope, God cannot forgive me." When we have such an attitude, we are commiting the grave sin of despair, where we say that God cannot or is incapable of forgiving us. This is blasphemy, plain and simple, since it denies the very core of God's being: His love and mercy.
So what should we do? We should constantly remind ourselves of God's immense mercy. We should not have any thought of despair, since God shows His love to us even if we are sinners, His mercy is without end and greater than our sinfulness, and His mercy enables such blanks in the movie of our life. May we grow closer to God with confidence, knowing that we have a loving and merciful God, who will care and provide for us.