the spirit of the law is luther

… If you teach others, but not your own selves, you do not know what you teach, and have not rightly understood the nature of the law. Nay, the law increases your guilt, as Paul says in [Romans 5:20]. A man only hates the law the more, the more it demands what he cannot perform.

That is why, in [Romans 7:14], Paul calls the law spiritual; spiritual, because if the law were corporeal, our works would meet its demands. Since it is spiritual, however, no one keeps it, unless everything you do springs from your inmost heart. Such a heart is given us only by God’s spirit, and this spirit makes us equal to the demands of the law. Thus we gain a genuine desire for the law, and then everything is done with willing hearts, and not in fear, or under compulsion.
—  Martin Luther, Preface to Romans
To fulfill the law, we must meet its requirements gladly and lovingly; live virtuous and upright lives without the constraint of the law, and as if neither the law nor its penalties existed. But this joy, this unconstrained love, is put into our hearts by the Holy Spirit [Romans 5:5]. But the Holy Spirit is given only in, with, and through faith in Jesus Christ, as Paul said [Romans 1] … Faith itself comes only through the Word of God, the gospel. This gospel proclaims Christ as the Son of God; that He was man; that He died and rose again for our sakes…
—  Martin Luther
… Where the Law accuseth me, death reigneth over me, and at length would devour me. But I have another righteousness and life above this life, which is Christ the Son of God, who knoweth no sin nor death, but is righteousness and life eternal: by whom even this my body, being dead and brought into dust, shall be raised up again and delivered from the bondage of the Law and sin, and shall be sanctified together with the Spirit.
—  Martin Luther