This is an article by theologian Robert Gagnon. He has twelve passages to prove his point, but I’ll only quote a few below.

He writes:

(5) Jesus referred to “the weightier matters of the law” (Matt 23:23) such as justice, mercy, and faith(fulness), which were more important to obey than the tithing of tiny spices, even though the latter too had to be done (Matt 23:23). These formulations imply that violations of weightier or greater commandments (like defrauding the poor of their resources for personal gain) are more severe than violations of lesser or ‘lighter’ commandments (like paying tithes on small foods likes spices), which Jesus stated should be done without leaving the weightier matters undone. Jesus adds the following criticism: “Blind guides, those who strain out the gnat but who swallow the camel” (23:24). What’s the difference between a gnat and a camel if all commands and all violations are equal?

(6) Jesus famously pinpointed the two greatest commandments (Mark 12:28-31). He also said, “Whoever relaxes one of the least of these commandments (of the law) and teaches the people (to do things) like this will be called least in the kingdom of heaven” (Matt 5:19). Again, to have greater and lesser commandments is to have greater and lesser violations.

(7) I would submit that Jesus’ special outreach to economic exploiters (tax-collectors) and sexual sinners, all in an effort to recover them for the very kingdom of God that he proclaimed, was not so much a reaction to their abandonment by society as an indication of the special severity of these sins and the extreme spiritual danger faced by such perpetrators. In this connection one thinks of the story of the sinful woman who washed Jesus’ feet with her tears, wiped his feet with her hair, kissed them with her lips, and anointed them with ointment (Luke 7:36-50). Jesus explained her extraordinary act by telling a parable of two debtors: the one whom the creditor “forgave more” would be the one who would “love him more.” The clear inference is that the sinful woman had done something worse in God’s eyes. Although Jesus’ Pharisaic host did not appreciate the woman coming into contact with Jesus, Jesus extolled the woman’s actions: “Therefore, I tell you, her sins, which were many [or: much, great], have been forgiven, for she loved much [or: greatly]; but the one who is forgiven little, loves little” (7:47). Many Christians treat the notion of being forgiven of greater sins as a bad thing. Jesus turns the idea on its head. Think about how Christians who stress that all sins are equal could use the biblical concept of some sins being more severe than others: Some of us may have needed more forgiveness, but I tell you that this has made us understand the Lord’s grace that much better and so love the Lord that much more.

(8) Another obvious instance of prioritizing some offenses as worse than others is Jesus’ characterization of “blasphemy against the Holy Spirit” as an “eternal sin” from which one “never has forgiveness”—in context referring to the Pharisees’ attribution of Jesus’ exorcisms to demonic power (Mark 3:28-30).

(9) According to John 19:11 Jesus told Pilate, “You would not have any authority against me if it had not been given to you from above. Therefore the one who handed me over to you has greater sin.” The reference is either to Judas (6:71; 13:2, 26-30; 18:2-5) or to Caiaphas the High Priest (18:24, 28). “Greater sin” obviously implies the Pilate’s action is a lesser sin.

Previously, I blogged about whether there are degrees of punishment in Hell, and degrees of rewards in Heaven.