Moral Perfection? God does not demand that we reach such destination; but He does expect that we make the Journey

The God of the Hebrews expects His people to walk towards the moral perfection outlined by His commandments; those written by Him upon the two stone tablets (don't worship other gods, don't make images of God, don't bear false witness, keep the Sabbath rest, don't steal, don't murder, honor your parents, don't covet, etc).
But the commandments are just “the horizon”; they are not the destination! In other words, God will hold us accountable for avoiding the Journey towards moral perfection [and not for being unable to attain such perfection! ].
That's why, as we embark in the journey, we often find that the Creator effectively limits the amount of good we are allowed to perform (by not giving us the required health, wisdom, courage, or resources to achieve it). And from whence do we know that Scripture validates this truth? We know it from the story of King David, who wanted to do the great good implied in building a house of praise and worship for the Creator.
But, in the end, God himself prevented him from doing the good he wanted. As it is written:
«Then David the king stood up upon his feet, and said, Hear me, my brethren, and my people: As for me, I HAD IN MINE HEART TO BUILD AN HOUSE OF REST FOR THE ARK OF THE COVENANT OF THE LORD, AND FOR THE FOOTSTOOL OF OUR GOD, AND HAD MADE READY FOR THE BUILDING: BUT GOD SAID UNTO ME, “THOU SHALT NOT BUILD AN HOUSE FOR MY NAME, because thou hast been a man of war, and hast shed blood”»- 1 Chronicles 28: 2-4 (King James Bible).
And the same is taught in the story of Jonah- although the sailors tried to do good (by not casting Jonah into the rough sea waters), God didn't allow it, but rather force them to throw him overboard. As it has been written:
«Nevertheless the men rowed hard to bring it to the land; but they could not: for the sea wrought, and was tempestuous against them. Wherefore they cried unto the Lord, and said, “We beseech thee, O Lord, we beseech thee, LET US NOT PERISH FOR THIS MAN'S LIFE, AND LAY NOT UPON US INNOCENT BLOOD: FOR THOU, O LORD, HAST DONE AS IT PLEASED THEE”.
SO THEY TOOK UP JONAH, AND CAST HIM FORTH INTO THE SEA: and the sea ceased from her raging”- Jonah 1: 13-15 (King James Bible).
Thus, the purpose of the many limitations God has imposed upon us is to provide the existential context required in order for us to understand the extend of God's power and glory; to show us that He isn't limited by our weakness and limitations.
As it has been written: “And Jonathan said to the young man that bare his armour, Come, and let us go over unto the garrison of these uncircumcised: it may be that the Lord will work FOR US: FOR THERE IS NO RESTRAINT TO THE LORD TO SAVE BY MANY OR BY FEW”- 1 Samuel 14: 6 (King James Bible).
And the fact that God doesn't depend on the strength [nor the perfection] of His people, is further attested in the verse that goes on to say: “And the Lord said unto Gideon, THE PEOPLE THAT ARE WITH THEE ARE TOO MANY FOR ME TO GIVE THE MIDIANITES INTO THEIR HANDS, LEST ISRAEL VAUNT THEMSELVES AGAINST ME, SAYING, MINE OWN HAND HATH SAVED ME”- Judges 7: 2 (King James Bible).

The error of claiming that “there’s no righteous man, as no man can perfectly keep the Law”

Who does the Torah (Hebrew Bible) says is considered righteous before God? Only the man who can perfectly keep the Law? Or, is God’s definition of righteousness, slightly different from that of our dear Christian brothers? Let’s see what the Hebrew Bible has to say about it:

1) “I have been young, and now am old; yet have I NOT SEEN THE RIGHTEOUS FORSAKEN, nor his seed begging bread”- Psalm 37: 25. Are there lies in the Hebrew Bible? Was David lying when he claimed he had seen many righteous men, but none forsaken?
2) “The wicked borroweth, and payeth not again: but THE RIGHTEOUS SHEWETH MERCY, AND GIVETH”- Psalm 37: 21. Do you pay your debts? Do you show mercy, and give unto those in need, even though you don’t owe them anything? Then God considers you a righteous man!
3) “For A JUST MAN FALLETH SEVEN TIMES, AND RISETH UP AGAIN: but the wicked shall fall into mischief”- Prov. 24: 16. A just [man] may fall [into sin], seven times [meaning every day of the week]; yet, if he rises up again (repents), he’ll still be called [by God] a just man.
4) “THE LORD REWARDED ME ACCORDING TO MY RIGHTEOUSNESS: according to the cleanness of my hands hath he recompensed me. For I have kept the ways of the Lord, and have not wickedly departed from my God. FOR ALL HIS JUDGMENTS WERE BEFORE ME: AND AS FOR HIS STATUTES, I DID NOT DEPART FROM THEM. I was also upright before him, and have kept myself from mine iniquity. THEREFORE THE LORD HATH RECOMPENSED ME according to my righteousness; ACCORDING TO MY CLEANNESS IN HIS EYE SIGHT”- 2 Samuel 22: 21-25.

Do you strive to do good, and never depart from God’s [ten] commandments? Then God sees you as a righteous man! But, what’s the precise meaning of “doing good”? Is it to believe that “Salvation is by faith” [without the need to obey God’s commandments]? Is it to believe that Jesus (peace be upon him) is the Messiah? Is it to believe in a blood atonement?
What does the Creator us to do? The answer is that God (blessed be He) only wants us to deal justly with our fellow human beings, to have mercy of the poor, and to renounce to pride and arrogance, as it is written: “He hath shewed thee, O man, what is good; and WHAT DOTH THE LORD REQUIRE OF THEE, BUT TO DO JUSTLY, AND TO LOVE MERCY, AND TO WALK HUMBLY WITH THY GOD? (Micah 6: 8).
Thus, if a man repents of his sins, he will be forgiven. And, if he commits himself to deal justly with his fellow human being, to have mercy, and to embrace a humble lifestyle, his righteousness will go before him, and the Lord will make His glory shine upon him, as it is written:
“Is it not to DEAL THY BREAD TO THE HUNGRY, and that thou BRING THE POOR THAT ARE CAST OUT TO THY HOUSE? WHEN THOU SEEST THE NAKED, THAT THOU COVER HIM; AND THAT THOU HIDE NOT THYSELF FROM THINE OWN FLESH? THEN shall thy light break forth as the morning, and thine health shall spring forth speedily: and THY RIGHTEOUSNESS SHALL GO BEFORE THEE; THE GLORY OF THE LORD SHALL BE THY REWARD.
Then shalt thou call, and the Lord shall answer; thou shalt cry, and he shall say, Here I am. IF THOU TAKE AWAY FROM THE MIDST OF THEE THE YOKE, THE PUTTING FORTH OF THE FINGER, AND SPEAKING VANITY; AND IF THOU DRAW OUT THY SOUL TO THE HUNGRY, AND SATISFY THE AFFLICTED SOUL; THEN SHALL THY LIGHT RISE IN OBSCURITY, AND THY DARKNESS BE AS THE NOON DAY:
AND THE LORD SHALL GUIDE THEE CONTINUALLY, AND SATISFY THY SOUL in drought, and make fat thy bones: and thou shalt be like a watered garden, and like a spring of water, whose waters fail not” - Isaiah 58: 7-14.