Final answer:
A mortal sin, in Christian theology, is a severe transgression that leads to separation from God's grace. It must be a grave matter, done with full knowledge and consent. Examples include murder and adultery, and forgiveness is possible through confession.
Step-by-step explanation:
To answer your question about mortal sin, we need to provide some context. In the context of Christian theology, a mortal sin is considered a grave transgression of God's law that leads to a complete separation from God's grace. The exact definition can vary between different denominations and religious teachings. Generally, for a sin to be classified as mortal, it must meet three conditions: it must be a grave matter, the person must have full knowledge that the action is sinful, and the person must give full consent to committing the act. Examples of mortal sins can include murder, adultery, or theft, among others. It's important to note that the notion of mortal sin is predominantly a concept within the Catholic Church, and other Christian denominations may not use this classification.
Mortal sins are contrasted with venial sins, which are lesser sins that do not result in a complete separation from divine grace. The Catholic Church teaches that mortal sins can be forgiven through the sacrament of confession, where the sinner repents, confesses, and resolves to amend their life.