I was asked about where in the Bible it speaks of deliberate or presumptuous sin so I decided to share it here also.

Old Testament examples:

Numbers 5:29

29 You shall have one law for him who does anything unintentionally, for him who is native among the people of Israel and for the stranger who sojourns among them.
30 But the person who does anything with a high hand, whether he is native or a sojourner, reviles the LORD, and that person shall be cut off from among his people.
31 Because he has despised the word of the LORD and has broken his commandment, that person shall be utterly cut off; his iniquity shall be on him.”

Psalms 19:13 Keep back your servant also from presumptuous sins;
let them not have dominion over me!
Then I shall be blameless,
and innocent of great transgression.

New Testament verses:

Hebrews 10: 26-31

26 For if we go on sinning deliberately after receiving the knowledge of the truth, there no longer remains a sacrifice for sins,
27 but a fearful expectation of judgment, and a fury of fire that will consume the adversaries.
28 Anyone who has set aside the law of Moses dies without mercy on the evidence of two or three witnesses.
29 How much worse punishment, do you think, will be deserved by the one who has spurned the Son of God, and has profaned the blood of the covenant by which he was sanctified, and has outraged the Spirit of grace?
30 For we know him who said, “Vengeance is mine; I will repay.” And again, “The Lord will judge his people.”
31 It is a fearful thing to fall into the hands of the living God.

James 4:17 So whoever knows the right thing to do and fails to do it, for him it is sin.

2 Peter 2:21 For it would have been better for them never to have known the way of righteousness than after knowing it to turn back from the holy commandment delivered to them.