On the last Thought I shared verses that say under the Law there was a remembrance of sin year after year and therefore there was sacrifice for sin year after year.
But Jesus came once for all time because He does what the blood of bulls and goats cannot do – cleanse all sin from your life.
If His sacrifice for sin wasn’t perfected then He would have to come back and die again and again for each sin you do. This would be an open shame.

Now this freedom FROM sin does not give you a freedom TO sin.
You cannot accept Jesus as Savior and then believe you can live as you want to or do anything you want, even though His blood cleanses you from all unrighteousness.

Rom 5:20 where sin abounded, grace abounded much more,
Rom 6:1-2 What shall we say then? Shall we continue in sin that grace may abound? Certainly not! How shall we who died to sin live any longer in it?

When you accept the Savior you die to sin. If you have not died to sin, have you really accepted the Savior?

Having been set free from sin, you became slaves of righteousness. I speak in human terms because of the weakness of your flesh. For just as you presented your members as slaves of uncleanness, and of lawlessness leading to more lawlessness, so now present your members as slaves of righteousness for holiness.
For when you were slaves of sin, you were free in regard to righteousness. What fruit did you have then in the things of which you are now ashamed? For the end of those things is death. But now having been set free from sin, and having become slaves of God, you have your fruit to holiness, and the end, everlasting life. For the wages of sin is death, but the gift of God is eternal life in Christ Jesus our Lord. Rom 6:18-23

What shall you say to those that accept Jesus and then seem to stray back into habitually sinning?
There are a couple of thoughts on this.

First, that the person would have to be saved again. That is not possible.
It is impossible for those who were once enlightened, and have tasted the heavenly gift, and have become partakers of the Holy Spirit, and have tasted the good word of God and the powers of the age to come, if they fall away, to renew them again to repentance, since they crucify again for themselves the Son of God, and put Him to an open shame. Heb 6:4-6

There is the idea that the person is eternally lost, for the wages of sin is death (Rom 6:23) and the soul who sins shall die. Ezek 18:4
But I am persuaded that neither death nor life, nor angels nor principalities nor powers, nor things present nor things to come, nor height nor depth, nor any other created thing, shall be able to separate us from the love of God which is in Christ Jesus our Lord. Rom 8:38-39
And we know that whoever is born of God does not sin; but he who has been born of God keeps himself, and the wicked one does not touch him. 1 John 5:18

There is the thought that this person is still redeemed but must answer for those sins.
For no other foundation can anyone lay than that which is laid, which is Jesus Christ. Now if anyone builds on this foundation with gold, silver, precious stones, wood, hay, straw, each one’s work will become clear; for the Day will declare it, because it will be revealed by fire; and the fire will test each one’s work, of what sort it is. If anyone’s work which he has built on it endures, he will receive a reward. If anyone’s work is burned, he will suffer loss; but he himself will be saved, yet so as through fire. 1 Cor 3:11-15

Jesus did not forgive you and redeem you so you CAN sin, but you are created in Christ Jesus for good works, which God prepared beforehand that we should walk in them. Eph 2:10