It is a good and searching prayer you have offered, and one which the Lord delights to answer, for you ask Him to do what only He can do, to examine the heart and to cleanse it within.
The word you have quoted is solemn, If someone curses their father or mother, their lamp will be snuffed out in pitch darkness. To dishonor those whom God has placed over us is not a light thing, for the command to honor father and mother is the first commandment with promise, and to despise it is to walk toward darkness. Yet how needful is your confession, for which of us has not in thought, in hasty speech, or in settled pride, failed in this duty. Some were blessed with pious parents and yet turned aside, and that very privilege makes the sin appear the greater. To feel this is itself a mercy, for it shows the Spirit is at work to make you tender and penitent.
Hear then the blessed whisper which meets every trembling heart that desires forgiveness, There is forgiveness with Thee. This is not a forgiveness which you must find out or earn, but a divine forgiveness, I, even I, am He that blotteth out thy transgressions. It is surprising forgiveness, so free and full that God Himself speaks as one who glories in it, and it is complete forgiveness. When you come to your creditor and say I have nothing to pay, He does not forgive a part, but the whole debt is nailed to the cross. He not only forgave at the first, but He continues daily to forgive, and His forgiveness is eternal. Whatever your age or history, however hasty your words or deep your resentment has been, there is forgiveness with God through Jesus Christ His Son, the Just dying for the unjust to bring us to God. There is forgiveness now, at this moment, for every repenting and believing sinner who looks to Christ alone, for salvation is through Jesus Christ alone and in no other.
You ask also that bitterness, pride and resentment may be taken away, and here is the power of the cross. When we truly mourn for Him whom we have pierced, and feel the bitterness of our sin against Christ, that holy bitterness makes Christ very sweet and it takes away all bitterness against our fellow men. The soul that has said, how much I offended God, and yet He has forgiven me, cannot hold fast to resentment. It must become sweet, gentle, kind, tender and forgiving toward others. Even as Christ forgave you, so also do you. This is the pattern set before us, and it is gloriously ennobling, for revenge is paltry but forgiveness is great minded. If you have received so much manifest forgiveness, to forgive ought to become as natural as to open your hands.
Therefore let us pray together that your lamp may be kept burning bright, not by your own strength, but by His truth, wisdom and grace.
Heavenly Father, we thank Thee for Thy word which is a lamp unto our feet, and for Jesus Christ the living Word, the Bread of Heaven. We confess before Thee that we have not always honored our father and mother as Thou hast commanded, but have sinned in thought, word and deed, in pride and hastiness of spirit. Forgive us, O Lord, for Jesus sake, and blot out our transgressions. Examine our hearts and cleanse away every root of bitterness, pride and resentment. Create in us a clean heart and renew a right spirit within us. Teach us to honor those Thou hast given us, and to walk in Thy light rather than stumble in darkness. Keep our lamp burning with Thy truth, and make us to be forgiving as we have been forgiven, to Thy glory. In the name of Jesus Christ our only hope and Redeemer we pray, Amen.