What is repentance?
 
(George Everard, "Welcome home! Plain teachings from the story of the Prodigal" 1871)

"I will set out and go back to my father and say to him: 'Father, I have sinned against heaven and against you. I am no longer worthy to be called your son; make me like one of your hired men.' So he got up and went to his father." Luke 15:18-20

Notice the spirit of deep self-abasement in the resolution which the prodigal made.

True repentance is intensely personal. The prodigal felt it was his own sin. "I have sinned!" He can scarcely see any sin but his own. He sees his own sin in the very worst colors. Study the fifty-first Psalm. See how David again and again speaks. It is my transgression, my iniquity, my sin ever before me.

True repentance beholds the wrong done to God by sin. The prodigal felt that his sin was primarily against God. It was a breach of His holy law. It was opposition to His holiness. It was sin against His goodness, and against redeeming love. So David cries in his bitter sorrow, forgetting for the moment the wrong he had done to Uriah - in the far greater wrong which his sin had done to God: "Against You, You only have I sinned, and done this evil in Your sight!"

True repentance makes no excuses. The prodigal seeks for no palliation, no covering, no cloak. He says nothing of the circumstances which led him to do evil, or of companions who had drawn him aside. He does not attempt to shift the burden from his own shoulders to that of others. He makes no self-justifying pleas - he has too much sorrow, too much true brokenness of spirit, to desire or attempt it. One thing, and one thing only, he sees - his own terrible fall, and his own exceeding guilt.

True repentance takes the very lowest place. Once to be a son was not enough for him - but now he will be content even to be a slave or a hired servant! He feels utterly unworthy. As Jacob felt: "I am not worthy of all the mercies You have showed me." As the centurion felt when he sent to Jesus: "I am not worthy that You should come under my roof." So did the young prodigal esteem himself: "I am no longer worthy to be called your son."

Be sure that God delights in the humble and contrite soul.
Lift yourself up in pride and self-satisfaction - and God will assuredly cast you down.
Cast yourself down in humble confession of your sin - and God will assuredly lift you up.
"God resists the proud - but gives grace unto the humble."

But we see here the purpose of the heart accomplished. The young man not only made the resolution, but he kept it, "So he got up and went to his father." He turned his back forever on that far country and his old companions - and turned his face homeward. Doubtless it was with many a tear, with many a bitter feeling of regret for all that had passed - since in so different a spirit he had trodden that path before. Yet onward he trudges with weary heart and weary footstep, in the hope that a place may still be found for him in his father's house.

Do you ask, What is repentance? I can scarcely better describe it than from the path of this wanderer. It is turning the back . . .
  on sin,
  on the ways of the world,
  on the lusts of the flesh,
  on the service of the devil.

And it is turning the face God-ward, Heaven-ward, confessing all that is past, looking upward for grace to live holier, with one single desire - to abide in the fear and love of God.