Mercy is defined as “not getting what you deserve,” that is each of us deserves going to hell. Grace is defined as “getting what you don’t deserve,” which means forgiveness, abundant life, and eternal life.
Jesus never uses the words mercy or grace in the Gospels. He shows. Later, Paul would tell. Jesus shows it with many people, including women. He tells one woman, “Neither do I judge you, go and sin no more.” So Jesus showed mercy to the women but also held her accountability. He did not say, “Go and do whatever you want.”
A woman he talked to at a well during the middle of the day. She had at least strikes against her: she was a woman (that was the case in those days), she was a Samaritan (in those days the Jews and Samaritans were the Hatfields and the McCoys of their time), and she was an outcast in her own village (that was why she was at the well by herself in the heat of the day). Jesus gently, yet firmly, guides her into truth. The amazing thing is that she understands the grace and love of Jesus. She races back to the town where people don’t want to talk with her and says, “This man knows all about me (and yet he still loves me). Can He be the Messiah?” This woman became an Evangelist to the people who hated her. The entire village walks out to see Jesus, looking like a field of wheat in their clothes. They come to Jesus and come to know him.
John 1:14 tells us that Jesus pitched His tent (lived) among humans and was full of grace and truth. He showed mercy and truth. He spoke forgiveness, mercy and grace without using those words.