Exactly. There's nothing you can do, one way or the other. So why are you worried about sin, if it's already been dealt with?
Just because we are saved doesn't mean we can freely Sin. We can't go on deliberately and willingly sinning after once acquiring the knowledge of the Truth. (Heb 10:26).
A Christian's life is to be characterized by practicing righteousness, purity and (Hebrews 12:14)
Strive to live in peace with everybody and pursue that consecration and
holiness without which no one will [ever] see the Lord.
Etc...
John 3:36
And he who believes in (has faith in, clings to, relies on) the Son has (now possesses) eternal life. But whoever disobeys (is unbelieving toward, refuses to trust in, disregards, is not subject to) the Son will never see (experience) life, but [instead] the wrath of God abides on him. [God's displeasure remains on him; His indignation hangs over him continually.]
1 Peter 2:16
[Live] as free people, [yet] without employing your freedom as a pretext for wickedness; but [live at all times] as servants of God.
Hebrews 10:26-30
26 For if we go on deliberately and willingly sinning after once acquiring the knowledge of the Truth, there is no longer any sacrifice left to atone for [our] sins [no further offering to which to look forward].
27 [There is nothing left for us then] but a kind of awful and fearful prospect and expectation of divine judgment and the fury of burning wrath and indignation which will consume those who put themselves in opposition [to God].(A)
28 Any person who has violated and [thus] rejected and set at naught the Law of Moses is put to death without pity or mercy on the evidence of two or three witnesses.(B)
29 How much worse (sterner and heavier) punishment do you suppose he will be judged to deserve who has spurned and [thus] trampled underfoot the Son of God, and who has considered the covenant blood by which [/B]he was consecrated common and unhallowed, thus profaning it and insulting and outraging the [Holy] Spirit [Who imparts] grace (the unmerited favor and blessing of God)?(C)
30 For we know Him Who said, Vengeance is Mine [retribution and the meting out of full justice rest with Me]; I will repay [I will exact the compensation], says the Lord. And again, The Lord will judge and determine and solve and settle the cause and the cases of His people.
1 John 3:6-9
6 No one who abides in Him [who lives and remains [a]in communion with and in obedience to Him--deliberately, knowingly, and
habitually] commits (practices) sin. No one who [habitually] sins has either seen or known Him [recognized, perceived, or understood Him, or has had an experiential acquaintance with Him].
7[a]Boys (lads), let no one deceive and lead you astray. He who practices righteousness [who is upright, conforming to the divine will in purpose, thought, and action, living a consistently conscientious life] is righteous, even as He is righteous.
8 [But] he who commits sin [who practices evildoing] is of the devil [takes his character from the evil one], for the devil has sinned (violated the divine law) from the beginning. The reason the Son of God was made manifest (visible) was to undo (destroy, loosen, and dissolve) the works the devil [has done].
9 No one born (begotten) of God [deliberately, knowingly, and habitually] practices sin, for God's nature abides in him [His principle of life, the divine sperm, remains permanently within him]; and he cannot practice sinning because he is born (begotten) of God.