Joshua (Joshua 24), after recounting God’s mercy and His faithfulness to the promises in delivering Israel from all her enemies, exhorts the Israelites to put away their false gods, to fear the LORD and serve Him in sincerity and truth. The Israelites essentially declare, “We will do it!” Joshua, truly understanding the perfection required by anyone who would serve God on the ground of their own works and also knowing the weak view the people had of the righteousness demanded by God, replies unto the people, "Ye cannot serve Jehovah; for he is a holy God; he is a jealous God; he will not forgive your transgression nor your sins.” They could not serve God in a holiness of their own and they could not atone for the pollution of their sins.
The Israelites had a need. It was that their watered-down law-keeping mindset had to be humbled and stopped in its tracks by the very Law that they presumed to fulfill. This was in order that they then might be lifted up by the LORD’s free mercy.
Calvin: “But Scripture humbles us more, and at the same time elevates us. For besides forbidding us to glory in works, because they are the gratuitous gifts of God, it tells us that they are always defiled by some degrees of impurity, so that they cannot satisfy God when they are tested by the standard of his justice; but that lest our activity should be destroyed, they please merely by pardon.” — i.e. God’s free mercy and pardon in Christ alone...
and in WCF 14:2,
“… But the principal acts of saving faith are accepting, receiving, and resting upon Christ alone for justification, sanctification, and eternal life, by virtue of the covenant of grace.“
“… the righteous acts of the saints.”
And how are the acts of the saints constituted righteous? By what merit? By what obedience? By their own intrinsic holiness? No. Indeed, by the Holy Spirit we have been given a new sanctified heart and will in order that we might now seek to obey, even obey completely. Yet in this life - though now saints yet remaining sinners - no thought, no word, no deed - no matter how “holy” - is without some stain of sin.
How is it then that we are not also rebuked, as were the Israelites, when we seek to serve God? Indeed often we are as the Holy Spirit brings us again and again to the foot of the cross that we would see the bankruptcy of our persons and of our works. And yet also, seeing and hearing the good news again, that we are accepted as righteous by God not by our works but due only to His free grace and mercy in Christ... the blessing of salvation that we receive and abide in through faith alone. We should never confuse our “righteous acts” in this life with the perfection required by the Law. Our works are acceptable only through the perfect obedience, merit, and mediation of our Savior and Advocate in heaven, Jesus Christ.
How is it then that we are not also rebuked, as were the Israelites, when we seek to serve God? Indeed often we are as the Holy Spirit brings us again and again to the foot of the cross that we would see the bankruptcy of our persons and of our works. And yet also, seeing and hearing the good news again, that we are accepted as righteous by God not by our works but due only to His free grace and mercy in Christ... the blessing of salvation that we receive and abide in through faith alone. We should never confuse our “righteous acts” in this life with the perfection required by the Law. Our works are acceptable only through the perfect obedience, merit, and mediation of our Savior and Advocate in heaven, Jesus Christ.
“The righteous shall live by faith.” As we seek to obey, it is through faith in Christ alone that our works are cleansed and lifted up to God. Our works rise up to God as acceptable only through the blood of Christ: “how much more shall the blood of Christ, who through the eternal Spirit offered himself without blemish unto God, cleanse your conscience from dead works to serve the living God?” The writer of Hebrews was writing to believers.
“for by grace have ye been saved through faith; and that not of yourselves, it is the gift of God; not of works, that no man should glory. For we are his workmanship, created in Christ Jesus for good works, which God afore prepared that we should walk in them.”
“Prepared” in that “he chose us in him before the foundation of the world, that we should be holy and without blemish before him in love: having foreordained us unto adoption as sons through Jesus Christ unto himself, according to the good pleasure of his will, to the praise of the glory of his grace, which he freely bestowed on us in the Beloved: in whom we have our redemption through his blood, the forgiveness of our trespasses, according to the riches of his grace…”
Yes, as Scripture teaches, it is all by grace. And as my wont - a quote from Calvin:
In regard to this liberty there is a remarkable passage in the Epistle to the Romans, where Paul argues, “Sin shall not have dominion over you; for ye are not under the law, but under grace,” (Romans 6:14) For after he had exhorted believers, “Let not sin therefore reign in your mortal body, that ye should obey it in the lusts thereof: Neither yield ye your members as instruments of unrighteousness unto sin; but yield yourselves unto God, as those that are alive from the dead, and your members as instruments of righteousness unto God;” they might have objected that they still bore about with them a body full of lust, that sin still dwelt in them. He therefore comforts them by adding, that they are freed from the law; as if he had said, Although you feel that sin is not yet extinguished, and that righteousness does not plainly live in you, you have no cause for fear and dejection, as if God were always offended because of the remains of sin, since by grace you are freed from the law, and your works are not tried by its standard.
I don’t think our obedience or Godly living is diminished or weakened by extolling the truth that salvation, start to finish, is by God's grace. Rather, our persons as well as our obedience are cleansed, purified, i.e. made acceptable through the satisfaction of Christ’s own perfect obedience and death. In sanctification the only sure ground upon which sinner/saints walk and live unto God is the grace of the gospel.