In today's gospel, Jesus predicts the betrayal of both Judas and Peter. The stories are parallel but differ in important points. Judas betrays Christ and later despairs while Peter repents. Judas does not think that God is great enough, or merciful enough to forgive him. Peter, on the other hand, weeps for his sins, but repents and goes on to lead the Apostles and the new Church.
We see these differences symbolically in this painting by Andrea del Castagno (1423-1457)Judas is shown in dark garments sitting across the table from Jesus. Peter, shown as the traditional wise old(er) man and future pope, sits on Jesus' right hand and John the Beloved Disciple sits on his left.
As long as we stay with Christ, we will be saved.
Let us fight against despair and always remember God's mercy is for us individually.