From the writings of the Rev. Billy Graham
When people cannot explain the unpardonable sin, it is unlikely that they have committed it; their feelings of guilt seem to support this conclusion.
The unpardonable sin involves the total and irrevocable rejection of Jesus Christ. It is void of guilt. Resisting the Holy Spirit of God is a sin committed by unbelievers that when carried on long enough, leads to eternal doom. Only certain judgment remains for those who resist the Holy Spirit that is sent by God to draw us to Himself.
It is not unusual for people to wonder if they have committed a deed that cannot be forgiven, such as murder, incest, abortion, or even something that may not seem quite so serious. Such people often develop obsessive guilt, perhaps not unlike David’s when he cried out, “My sin is always before me. Against You [God] … have I sinned” (Psalm 51:3-4).
It seems that no one has committed this sin who continues to be under the disturbing, convicting, and drawing power of the Holy Spirit. So long as the Spirit strives with a person, he or she has not committed the unpardonable sin. But when a person has so resisted the Spirit of God that He strives with him or her no more, then there is eternal danger.
What is the answer, then, to this overwhelming guilt? Each person must humble themselves before God and admit their sin. Cry out, “God, be merciful to me a sinner!” (Luke 18:13). Recognizing and confessing sin is a prerequisite to all else that follows. God is in the business of forgiving sin. He sent His son to the cross “that we might become the righteousness of God in Him” (2 Corinthians 5:21). For believers, “to testify to the gospel of the grace of God” brings great joy (Acts 20:24).
(This column is based on the words and writings of the late Rev. Billy Graham.)