Before we prepare our heart to come to the altar in prayer our heart must be right with man. After providing his disciples the Lord’s Prayer, the Lord specifically highlights the importance of forgiveness (credit to Tim Keller in his book on prayer for pointing this out).
“For if you forgive others their trespasses, your heavenly Father will also forgive you, but if you do not forgive others their trespasses, neither will your Father forgive your trespasses.” (Matthew 6:14-15 English Standard Version).
Earlier in the Book of Matthew the Lord discusses the importance of being in a state of peace among men before coming to pray.
“So if you are offering your gift at the altar and there remember your brother has something against you, leave your gift there before the altar and go. First be reconciled to your brother, and then come and offer your gift.” (Matthew 5:23-24 ESV).
And this is affirmed in the Book of Mark as well.
“And whenever you stand praying, forgive, if you have anything against anyone, so that your Father also who is in heaven may forgive you your trespasses.” (Mark 11:26 ESV)
So we see how important it is to be in a right relationship with our fellow man before approaching the altar in prayer. Therefore, I beseech you brethren if there are people you have not forgiven for past transgressions to please forgive them (or if you can’t get there, pray that you will be made willing to forgive) and let us be at peace with each other.