The Lord's Prayer is prayed at every worship service or mass. We communally pray often just by rote, it is so familiar. But recently I've been stopped by the Fifth Petition and have spent a lot of time pondering this. "Forgive us our trespasses as we forgive those who trespass against us." Or, Forgive us our debts as we forgive our debtors."
When I really think about this I realize this is a very difficult thing to do and the seriousness of what I'm praying either with the rest of the congregation or privately hits me hard.
"Inasmuch as we sin greatly against God every day and yet He forgives it all through grace, we must always forgive our neighbor who does us harm, violence, and injustice [and] bears malice toward us.... If you do not forgive, do not think that God forgives you" (Large Catechism III:94-95)."
"Matt. 6:14-15 If you forgive men when they sin against you, your heavenly Father will also forgive you. But if you do not forgive men their sins, your Father will not forgive your sins."
How hard it is to forgive and mean it. How awful it is to realize that by not forgiving, we aren't forgiven.