There are a few verses that allude to the concept that there are sins that are greater and less.
Sin unto death and sin not unto death.
1 John 5:16-17 KJV
16 If any man see his brother sin a sin which is not unto death, he shall ask, and he shall give him life for them that sin not unto death. There is a sin unto death: I do not say that he shall pray for it.
17 All unrighteousness is sin: and there is a sin not unto death.
Weigheir matters of the law.
Matthew 23:23 KJV
23 Woe unto you, scribes and Pharisees, hypocrites! for ye pay tithe of mint and anise and cummin, and have omitted the weightier matters of the law, judgment, mercy, and faith: these ought ye to have done, and not to leave the other undone.
Greater and lesser commandments
Matthew 5:19 KJV
19 Whosoever therefore shall break one of these least commandments, and shall teach men so, he shall be called the least in the kingdom of heaven: but whosoever shall do and teach them, the same shall be called great in the kingdom of heaven.
Punishments graduated according to severity.
Hebrews 2:2 KJV
2 For if the word spoken by angels was stedfast, and every transgression and disobedience received a just recompence of reward;
Deuteronomy 25:2-3 KJV
2 And it shall be, if the wicked man be worthy to be beaten, that the judge shall cause him to lie down, and to be beaten before his face, according to his fault, by a certain number.
3 Forty stripes he may give him, and not exceed: lest, if he should exceed, and beat him above these with many stripes, then thy brother should seem vile unto thee.
Exodus 21:23-25 KJV
23 And if any mischief follow, then thou shalt give life for life,
24 Eye for eye, tooth for tooth, hand for hand, foot for foot,
25 Burning for burning, wound for wound, stripe for stripe.
Greater and fewer stripes according to obedience.
Luke 12:47-48 KJV
47 And that servant, which knew his lord's will, and prepared not himself, neither did according to his will, shall be beaten with many stripes.
48 But he that knew not, and did commit things worthy of stripes, shall be beaten with few stripes. For unto whomsoever much is given, of him shall be much required: and to whom men have committed much, of him they will ask the more.