That’s true too, of course, but the purpose is not so we know we are sinners. It’s so we don’t steal or murder or desire that which belongs to another because it’s wrong.
(Gal 3:19)
Why, then, the Law [what was its purpose]?
It was added [after the promise to Abraham,
to reveal to people their guilt] because of transgressions [
that is, to make people conscious of the sinfulness of sin], and [the Law] was ordained through angels and delivered to Israel by the hand of a mediator [Moses, the mediator between God and Israel, to be in effect] until the Seed would come to whom the promise had been made. AMP
(Gal 3:19) Why then was the law given? It was added for the sake of transgressions until the Seed to whom the promise was made would come. The law was put into effect through angels by means of a mediator. CSB
(Gal 3:19) Why then the law? It was added because of transgressions, until the offspring should come to whom the promise had been made, and it was put in place through angels by an intermediary. ESV
(Gal 3:19) Why then was the law given? It was added because of transgressions, until the arrival of the descendant to whom the promise had been made. It was administered through angels by an intermediary. NET
(Gal 3:19) Why the Law then? It was added because of transgressions, having been ordained through angels by the agency of a mediator, until the seed would come to whom the promise had been made. NASB
The law demanded but gave no power to do:
(Rom 7:18) For I know that nothing good dwells in me, that is, in my flesh;
for the willing is present in me, but the doing of the good is not. NASB
(Rom 7:18) For I know that nothing good lives in me, that is, in my flesh. For I want to do the good, but I cannot do it. NET
(Rom 7:18) For I know that nothing good dwells in me, that is, in my flesh. For I have the desire to do what is right, but not the ability to carry it out. ESV
(Rom 7:18) For I know that nothing good lives in me, that is, in my flesh. For the desire to do what is good is with me, but there is no ability to do it. CSB
(Rom 7:18) For I know that nothing good dwells within me, that is, in my flesh. I can will what is right, but I cannot perform it. [I have the intention and urge to do what is right, but no power to carry it out.]
I stand with Scripture, not your meager opinions.