Grace and mercy are two of the greatest gifts from God. For clarification, they are two very different things and important to distinguish. The difference between grace and mercy is that grace is the gift of freedom from the penalty of which we don’t deserve, and mercy is forgiveness from what we do deserve. For example, grace is not punishing a baby for crying, mercy is not punishing a man who chose to commit murder. Grace involves unconscious and unpreventable naivety, mercy involves conscious willing intent or conscious reluctant action through weakness.
Grace: Grace is not deserved. It is also not earned. Grace is a gift. It is an extension of patience and trust through our imperfect human nature.
Mercy: Mercy is the sparing of the harm or punishment one deserves for sin. Similar to grace, it is not earned, however, it is deserved. It is the moment one is given another chance even though everything points to guilt.