Many Christians are misguided and confused about mercy.
Mercy is not removing consequences from unrepentant sinners.
Mercy is for those who do confess and are repentant and only by the victims of the offenders.
And, mercy is not always removing consequences but maybe allowing someone to go through the consequences even if they are repentant. Consequences teach important lessons that impact the offender.
When we show mercy to a murderer, the person they killed is not around to extend that mercy, therefore no one else has a right to forgive and show mercy who was not the victim.
Hebrews 4:16
Let us then with confidence draw near to the throne of grace, that we may receive mercy and find grace to help in time of need.
God extends mercy to those who admit their guilt and desire mercy. He does not extend mercy to the evildoer who will not repent.
Titus 3:5
"He saved us, not because of works done by us in righteousness, but according to his own mercy, by the washing of regeneration and renewal of the Holy Spirit,"
Proverbs 21:21
"Whoever pursues righteousness and kindness will find life, righteousness, and honor."
God is very rich in mercy when we are repentant about our sinfulness. He even died to pay for our sin and extended mercy to us, but one must want it, pursuing God in brokenness over sin before that mercy is extended.
Only the victim of a crime has the right to forgive or extend mercy and only if that person shows remorse. The judge can do this too on behalf of the victims but should always allow the victims to be the ones to decide.
A criminal who is repentant should always expect punishment. Those who demand mercy and desire no consequences are likely not remorseful.
