All sin is equally against God, and we will be held accountable by God for every sin. While this is true, the greatest sin is rejecting the Holy Spirit’s call to salvation in Christ.
When Adam and Eve rebelled, all of creation came under the curse of sin. For humanity, this resulted in a sin nature that is rebellious against God from birth (Psalm 51:5; Jeremiah 17:9). It is because of this nature that we commit individual acts of sin. We sin because it is in our nature.
All acts of sin are equally sinful in God’s sight. There is no worse sin, because all sin separates us from God. However, all sin is also equally forgivable if we come to Christ, who died on the cross for our sins. All who trust in Him for the forgiveness of sins through His death and resurrection will be saved and their sins will be forgiven. While all sin is equally condemnable, all sin is also equally forgivable. At the same time, some sin is worse than others in terms of consequence. Actions committed have more serious consequences than those in the mind, although both sins are equally condemnable.
There is one sin, though, the consequences of which are permanent and irrevocable. In this sense, this sin is the greatest sin. The blasphemy of the Holy Spirit is not forgivable. This sin is rejecting the Holy Spirit’s conviction, or the hardening of one’s heart, rejecting Christ’s salvation and resulting in eternal separation from God.
Recognizing that all sin separates us from God is a sobering reminder of the seriousness of sin and its consequences. This understanding calls for a genuine response, including a careful examination of our heart and actions, sincere repentance, and seeking God's forgiveness through Christ. The Bible's teaching on the unforgivable sin—the rejection of the Holy Spirit's call to salvation—reveals the urgency of embracing God's grace. This awareness should inspire a commitment to live in a way that honors God, actively listening to the Holy Spirit, and being open to correction. It also encourages sharing the message of salvation with others, emphasizing the importance of responding to God's offer of grace.
While sin is serious, the greater truth is that God's grace is available. Knowing that we will sin should humble us; but knowing that God’s grace is sufficient for our sin should also bring us humbly to Him, knowing He loves us and wants what is best for us. Psalm 1:1-2 tells us how we should respond to sin and what we should pursue instead: "Blessed is the man who walks not in the counsel of the wicked, nor stands in the way of sinners, nor sits in the seat of scoffers; but his delight is in the law of the LORD, and on his law he meditates day and night."