a) What is sin?
Sin is any willful thought, desire, word, action, or omission against God’s law. The sins we commit are also called “actual sins,” to distinguish them from “original sin,” which is a state of sinfulness rather than a committed sin. Sin may be mortal or venial.
Mortal sin is a grievous offense against our loving God. The effects of mortal sin are: it deprives one of sanctifying grace; it makes one an enemy of God, and harms oneself and the Church spiritually; it takes away the merit of all of one’s good actions; it deprives one of the right to go to heaven; it makes one deserving of hell. To make a sin mortal, three things are necessary: serious matter, full knowledge, and deliberate consent.
Venial sin is a less serious offense against our loving God, and does not deprive the soul of sanctifying grace. It harms us by making us less fervent in the service of God, by weakening our power to resist mortal sin, and by making us deserving of God’s punishments in this life or in purgatory.
b) How can an Altar Server avoid sin?
We can avoid sin by praying, going to Confession frequently, remembering that God is present everywhere, keeping ourselves busy, and rejecting temptations immediately.
We should also help others avoid sin, first, by being good examples to them, becoming their friends, and teaching and encouraging them, especially when we see them weak or not struggling enough.