Mercy comes from God, by request and belief in Christ. I can not show it to the merciless. Only He can.
Are you saying that you have never extended mercy to your teenager when they came in 5 minutes after their set curfew time?
Or that you never donated food to an organization that helps with the hungry or homeless?
Do you need to get a new church with some doctrine that follows Christ’s example. How many times did he display mercy toward the blind, the sick, etc.?
Did you ever carry a wounded buddy off the battlefield? That was “mercy” if you did so.