John Bunyan, answered from the texts and cited to the page.
A sinner stands just before God by a righteousness that is not his. It is the obedience of one man, Christ, reckoned to him, because the law calls for perfect righteousness and God cannot bestow any other blessing on a man until such a righteousness is found upon him. By the law he has pronounced the sinner accursed, and the sinner stays held by that curse until there is a righteousness the law and divine justice can both approve.1
That righteousness stays where it was. It resides in Christ, not in us, even while we stand just before God by it, as the wing and feathers still abide in the hen when the chickens are covered and warmed beneath them. My doings feed my children and are still my doings, not theirs. Our sins laid on Christ were personally ours, not his, and so his righteousness put upon us is personally his, not ours.2
It is one of the greatest mysteries in the world, that a righteousness that dwells with a person in heaven should justify me, a sinner, on earth. And I say it must come first, because Christ is head of the church and must have the pre-eminence in the soul. If grace were in the man before his justifying, I would ask what it should do there, or how it got in, since he stood condemned and God could not in justice give it to him until he was quit of the condemnation.3
Besides, if holiness were found first in those God pardons, the ground of the pardon would seem to be that he first found goodness in thee and me. The Scripture refutes that: there is none righteous, no, not one.4 Christ died for the ungodly, and while we were yet sinners, and enemies, the reconciling was done.5 So the poor soul is to reckon himself a sinner, and as a sinner to reckon himself justified, taking it freely as one worthless and undeserving, not for anything in him or done by him.6
Now to your second question. It is a fair one, and the Pharisee asks it. Hear how I answer it. Holiness has not lost its reason. It has its right place, and the place is after the pardon. When Christ ascended he received gifts for men: faith, hope, love, an upright heart, humbleness of mind, every part of what the word of life counts holiness.
God laid them up in him so that we who fly to him might have help for both righteousness and gospel sanctity.7 All graces are in Christ, and are infused into those whom he justifies, so that he might be the whole of the sinner's happiness.7 Justification is the root, and sanctification follows from it as fruit from the tree, the blessing of Abraham coming upon the forgiven man, the promise of the Spirit through faith.1
The man who is justified is therefore anything but idle. He has simply learned where his righteousness lies, and has left off lodging it in himself. There is a further reason I would give for the plainness of the thing. The law and the works of it must be cast away in this matter. They are useless, since salvation comes by another name, and they are a hindrance, since clinging to the law, though it be in but a little part, prevents justification by the righteousness of Christ.2
The man who looks for a righteousness in himself will be at a loss in temptation, but he who looks to Jesus has peace and safety nowhere else.2 And the Christian is not to follow his sense and feeling, but the very Word of God, giving more credit to one syllable of the Gospel than to the devil and his own guilty conscience. Think of a traitor whose king has sent him a pardon under his own hand and seal. He honours his king more by believing the handwriting than by regarding the clamours of his enemies.8
The righteousness by which a sinner stands before God is not in him but in Christ, and it is reckoned to him when he believes. The law as a covenant of works condemns every man who seeks life by it, the moralist most of all, because he thinks he has kept it. Fowler's holiness of a purified nature is the old heart in better clothes. Holiness follows justification as fruit follows the root: grace does not leave a man idle, it makes him new, and a holy life is the beauty of the faith.910111213
Justifying righteousness, to wit, the obedience of that one man Christ is imputed to the sinner to justify him in God's sight. For his law calls for perfect righteousness, and before that be come TO, and put UPON the poor sinner, God cannot bestow other spiritual blessings upon himA Discourse upon the Pharisee and the Publican
Mark, the righteousness is still 'in him,' not 'in us,' even then when we are made partakers of the benefit of it; even as the wing and feathers still abide in the hen when the chickens are covered, kept, and warmed thereby.Justification by an Imputed Righteousness
Christ is head of the church, and therefore let him have the highest honour in the soul; but how can he have that, if any precede as to justification, before his perfect righteousness be imputed?A Discourse upon the Pharisee and the Publican
Besides, if holiness should first be found In those whom God doth pardon, then the ground Why we forgiven are would seem to be, He first found holiness in thee and meOne Thing Is Needful; Ebal and Gerizzim
But God commended his love toward us, in that, while we were yet sinners, Christ died for us.A Discourse upon the Pharisee and the Publican
not for anything that is in thee, or done by thee, but freely as thou art a sinner, and so standest in absolute need thereof.The Doctrine of the Law and Grace Unfolded
Faith, hope, and love, true zeal, an upright heart, Right humbleness of mind, and every part Of what the word of life counts holiness, God then laid up in him, that we redress And help might haveOne Thing Is Needful; Ebal and Gerizzim
Now which way should this man so honour his king, but as by believing his handwriting, which was the pardon.The Doctrine of the Law and Grace Unfolded
A HOLY LIFE THE BEAUTY OF CHRISTIANITY: or, AN EXHORTATION TO CHRISTIANS TO BE HOLY. BY JOHN BUNYAN. Holiness becometh thine house, O Lord, for ever.'--[Psalm 93:5] London, by B. W., for Benj. Alsop, at the Angel and Bible, in the Poultrey. 1684.A Holy Life the Beauty of Christianity
'Wherefore, my brethren, ye also are become dead to the law [the moral law, and the ceremonial law] by the body of Christ, that ye should be married to another [another than the law] even to him who is raised from the dead, that we should bring forth fruit unto God' (Rom 7:4). Ye are become dead to the law. Dead to the law! Why? That you should be married to another. Married to another! Why?A Defence of the Doctrine of Justification by Faith
Yet this worketh in us no looseness, nor favour to sin, but so much the more an abhorrence of it: 'She loveth much, for much was forgiven her' (Luke 7:47). Yea, she weeps, she washeth his feet, and wipeth them with the hairs of her head, to the confounding of Simon the pharisee, and all such ignorant hypocrites.A Defence of the Doctrine of Justification by Faith
And hence it is that holy men stand just in the sight of God from the curse; yet dare not offer their gifts by the law, but through Jesus Christ; knowing that not only their persons, but their spiritual service also, would else be rejected of the heavenly Majesty (1 Peter 2:5; Rev 7:14-16; Heb 8:7,8).Justification by an Imputed Righteousness
But what do you mean by these words—the old covenant as the old covenant? Explain your meaning. Answ. My meaning is, that the Law is not to be looked upon for life, so as it was handed out from Mount Sinai, if ever thou wouldst indeed be saved; though after thou hast faith in Christ, thou mayest and must solace thyself in it, and take pleasure therein, to express thy love to Him who hath already saved thee by His…The Doctrine of the Law and Grace Unfolded
The centre of his theology and the ground of his quarrel with the Latitudinarians; charged by Fowler and suspected by Baxter of antinomianism, which he denied in every book on conduct he wrote.