Lent Reflections Week 4: Mercy

I have some difficulty with this word, which probably stems from its frequent pairing with the word sin in Christianity:
"Lord Jesus Christ, Son of God, have mercy on me, a sinner."
However, if we look to the Psalms or the Qur'an, we see that it is most often paired with the word compassion.
"The Lord is gracious, and full of compassion; slow to anger, and of great mercy. The Lord is good to all: and his tender mercies are over all his works." Psalm 145:8-9
Every surah of the Qur'an starts with the words, "In the name of Allah, the compassionate, the merciful."
The word compassion means suffering with. Whilst it is possible to show mercy without feeling compassion or to feel compassion without showing mercy, more often mercy flows from compassion. If we feel someone else's suffering, we are likely to behave in a kind and forgiving way towards them. What we give out flows back to us.
"Blessed are the merciful, for they shall obtain mercy." Matthew 5:7