Daniel 9:4-10 / Luke 6:36-38
We know how traitors and betrayers are usually dealt with.
It is usually the death sentence. If not then they will be thrown into a jail and remain in captivity for the rest of their lives.
In between there can be various forms of torture and torment to make the traitor or betrayer pay for what they have done.
In the 1st reading, the prophet Daniel cried out to the Lord for forgiveness.
For him, sin of his people took the form of a betrayal - "We have betrayed Your commandments and Your ordinances ... "
He called his people traitors because "of the treason we have committed against You".
So by ordinary human judgement, the people of Israel ought to be annihilated. Because they have done the unforgivable - they have sinned against God.
That would also be our sentence. Who can say he has no sin? Who can say that he does not deserve punishment for his sin?
Yet the Lord our God is compassionate and merciful and will forgive.
Yet we must truly repent and turn back to God. Not to do so would be to betray God's love for us and commit treason against Him.
Yes, we must repent and beg for forgiveness because we won't be able to withstand the punishment for our sins.