Mortal and venial sin – the difference

Let’s begin with baptism, which does an extraordinary thing. It raises us immediately above our natural life and draws us into the mystery of the love of the Father, Son and Holy Spirit. This love is dynamically intense, uniting the three persons so perfectly that they are one God.

Baptism unites us with that pure love, but it also demands that we love the people around us. Jesus told us that that the greatest commandment is to love God and, at the same time, to love our neighbour. You can’t have one without the other (1 Jn 4:20). We are all one in Christ.

So, when we sin, we show less than love for God and neighbour, sometimes even hatred. This interferes with our life in God and can completely separate us from his grace, although God never stops loving us.

It is this love that invites us to repent for our sin. If we refuse or ignore the invitation, the question must be asked: have we killed the life of God in us (mortal sin) or have we only diluted it by our pride (venial sin)?

The Church accepts and teaches that God forgives all sin as soon as the sinner heartily repents. But sin also harms the body of the Church, that is the faithful, and the classic distinction between mortal and venial sin arose from the way in which the Church administered the sacrament of penance.

Grievous sins such as murder and adultery do more than just break the law of God. They break the precious bond of love between us and God, and us and our neighbour. The sinner needs to be reconciled with the rest of the Church whose common vocation is to love God and neighbour. The Church has guided both priest and penitent to recognise mortal sin as one in which offenders have gambled away their chance of living for ever in God. Such sin needs absolution in the sacrament of penance.

Venial sin is characterised as a sin, such as small theft or lying, that does not, after repentance, necessarily need sacramental absolution.