We are not happy because we are unforgiving, and we are unforgiving because we feel superior to others.
Mercy is the fruit of the highest degree of love, because love creates equals, and a greater love makes us inferior.
First let us establish three premises:
Those who do not love feel superior to everyone else.
Those who love feel equal to everyone else.
Those who love much gladly take the lower place.
Each one of us can identify his position somewhere along this spectrum, which comprises the three degrees of the spiritual life here on earth:
Death for those who do not love.
Life for those who love.
Holiness for those who love much.
It is the beatitude of the merciful that Jesus himself lived to the full, stooping, out of love, to the lowest place, even to the extent of being rejected a common criminal, fit only to be hung on a gibbet.
----From In Search of the Beyond by Carlo Carretto
A prayer practice I have found helpful when I am tempted to look down on others is this breath prayer, known as The Jesus Prayer, “Lord Jesus, Son of God, have mercy on me, a sinner.”