Are our sins not forgiven after becoming a Christian? A conversation with a friend

Hebrews 10:26, 27
Tough words.

I'm in Denver through Wednesday. Just read this this morning. Author seems to imply that sins after accepting Christ aren't covered by His sacrifice. I don't have study materials or more time at the moment. I am teaching this Sunday and thought I would do a highlight of Hebrews, since that is what I have been reading.  Can you help me with these two verses, please?

In Christ,
Christian Friend

Hey brother!

Thanks for the question. I hope your trip in Denver is great. J

24 And let us take thought of how to spur one another on to love and good works, 25 not abandoning our own meetings, as some are in the habit of doing, but encouraging each other, and even more so because you see the day drawing near. 26 For if we deliberately keep on sinning after receiving the knowledge of the truth, no further sacrifice for sins is left for us, 27 but only a certain fearful expectation of judgment and a fury of fire that will consume God's enemies. 28 Someone who rejected the law of Moses was put to death without mercy on the testimony of two or three witnesses. 29 How much greater punishment do you think that person deserves who has contempt for the Son of God, and profanes the blood of the covenant that made him holy, and insults the Spirit of grace? (Heb 10:24-29 NET)

In context the author is speaking of the need for Christians to gather together in order to keep one accountable to “love and good works” (i.e., ethical, Christian actions). He then moves to remind them that if they don’t keep “spurning each other” in their church meetings, then they run the risk of continually sinning, which, of course, means a person will not be saved. The translation here (NET) is good. The Greek in v. 26 speaks of a person “willingly sinning” after receiving the gospel who has not received the atoning death of Jesus. To keep on sinning after becoming a disciple is tantamount to having “contempt for the Son of God,” “profaning the blood” of Jesus, and “insulting the Spirit of grace” (v. 29).

New Testament authors were quite adamant about this point: disciples of Jesus are to cease sinning. Paul (Rom 6; 8:2; 1 Cor 15:34), this author of Hebrews, John the Elder (1 Jn 2:1-2; 3:8), and Peter (1 Pet 2:24) all emphasize the fact that Christians are to cease sinning. It is a constant assumption in the NT that only pagans without the Spirit keep sinning (e.g., 2 Pet 2:14). So, the author of Hebrews fits nicely into a widely-held view among first century Christians that a Christian is one who does not continue in sin.

Can a Christian sin? Of course. This is why there are individual cases mentioned in the NT. The early Christians believed that if a person was committing a particular sin, then that person should be approached and helped to stop (Matt 18:15f; Gal 6:1-2; 1 Cor 5:4-5; 1 Jn 2:1-2). However, for a person to continue in sin, especially after having been encouraged/supported to stop sinning, then that person (according to the NT), is not a Christian. When that happened in Corinth (1 Cor 5:-45), Paul told them to kick the guy out of the church (“hand him over to Satan”).

(Now, maybe a good lunch conversation would be to reconcile the fact that we are told to offer “infinite” forgiveness to other humans who have offended us (Matt 18:21-35), while the early Christians didn’t believe God offered us infinite forgiveness if we were to keep on sinning toward Him.)

So . . . I need your help to stop sinning brother!