In one sense, all sins are equal before God. "All have sinned and fall short of the glory of God" (Roman 3:23). Ecclesiastes 7:20 makes clear, "Surely there is not a righteous man on earth who does good and never sins." All sin separates us from God and, apart from Christ, will separate us from Him eternally. In regards to salvation, there is no distinction. However, there are, of course, varying consequences of sin. For instance, murder carries greater consequences both to its victims and its perpetrator than does speaking angrily. But the Bible gives no list that ranks sin or describes a sin that is the "greatest."
Is there a sin that is worse than all the others? What is the greatest sin?
Even so, three other ways of discussing the "greatest sin" are mentioned in the Bible. First, Jesus told Pilate in John 19:11, "You would have no authority over me at all unless it had been given you from above. Therefore he who delivered me over to you has the greater sin." Jesus referred to Judas Iscariot, the disciple who had betrayed Him. In this context, the sin of Judas was willful, but the sin of Pilate was passive. Both were sins, yet Jesus stated that the sin of Judas was greater.
Perhaps Jesus meant that Judas' sin was greater in impact or was considered worse because Judas had thought and planned his betrayal for some time. Regardless, the end result was that both Judas and Pilate sinned in their response to Christ.
Second, Proverbs 6:16-19 includes seven sins the Lord hates. They include, "haughty eyes, a lying tongue, and hands that shed innocent blood, a heart that devises wicked plans, feet that make haste to run to evil, a false witness who breathes out lies, and one who sows discord among brothers."
While God despises these practices, He does not call them worse than others. Rather, they are sins that stand out, as well as sins that represent many other specific ways in which people sin against God. Further, it is a list of sins, not singling out any one sin as worse than all others.
Third, the Bible also mentions an unforgivable sin or unpardonable sin in Matthew 12:22-32 and Mark 3:22-30. Matthew 12:32 notes, "And whoever speaks a word against the Son of Man will be forgiven, but whoever speaks against the Holy Spirit will not be forgiven, either in this age or in the age to come." While there are various interpretations of this passage, the most likely understanding is that the unforgivable sin was the rejection of Jesus and His work by the power of the Holy Spirit.
Today the unpardonable sin is understood to be the sin of continued unbelief in Christ. Why? All sins can be forgiven by the Lord Jesus Christ. First John 1:9 declares, "If we confess our sins, he is faithful and just to forgive us our sins and to cleanse us from all unrighteousness." Therefore, the only sin that cannot be forgiven is to reject Christ and the forgiveness He offers. So, in that sense, the "greatest sin" is not believing in Jesus.
How can a Christian avoid some of the sins mentioned above? Psalm 1:1-2 offers great insight: "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."
What is sin?
Does God hate sin? Why?
Does the Bible have a list of sins?
How can I know what is a sin and what isn't?
Is there an unpardonable sin? What is it?
Truth about Sin