<< The Foundation of Justification
1. The merit of our Lord becomes ours “by faith.” “Through Him all that believe are justified” (Acts 13:39). Here, again, the Latin distinction is clear and significant. We are justified propter meritum Christi, but per fidem. Faith is never associated with the ground of Justification, but only as its means or channel. And all the New Testament references to faith indicate this in the clearest possible way.  Trust implies dependence upon another and the consequent cessation of dependence upon ourselves. Faith is, therefore, the acknowledgment of our own inability and the admission of our need of another’s ability. Faith links us to Christ and is the means of our appropriation of His merit. The full meaning of faith in the New Testament is trust. (1) The primary idea is belief in a fact (ὅτι, 1 John 5:1); (2) the next is belief in a person’s word (μοι, John 4:21); (3) but the fullest is trust in a person (ἐις, John 3:16). Thus, faith in its complete sense includes the assent of the mind and the consent of the will, the credence of the intellect and the confidence of the heart. As such, it is best understood as trust, the attitude of one person to another. 
2. The reason why faith is emphasised is that it is the only possible answer to God’s revelation. From the earliest days this has been so. The word of the Lord came to Abraham and he at once responded by simple trust (Gen. 15:1-6). To the same effect are the various illustrations of faith in Hebrews 11, all implying response to a previous revelation. As between man and man the absence of faith is a barrier to communion, so it is in things spiritual. Faith in man answers to grace in God. Faith is the correlative of promise. Trust answers to truth; faith renounces self and emphasises God’s free gift.  There is no merit in faith. It is self-assertion with a view to self-surrender. As Hooker has said, “God doth justify the believing man, yet not for the worthiness of his belief, but for His worthiness Who is believed.”  We are not justified by belief in Christ, but by Christ in Whom we believe. Faith is nothing apart from its Object, and is only valuable as it leads us to Him who has wrought a perfect righteousness, and as it enables us to appropriate Him as the Lord our righteousness. 
The question of Baptism is often discussed in relation to faith, and it is sometimes argued that faith tends to make us dispense with Sacraments. But this is not the case. The Sacrament of Baptism is not a channel, which is the old opus operatum theory; it does not convey the germ of life, but only provides the sphere in which that germ may express itself and grow. The true idea of Baptism is, therefore, covenantal  as the seal of an already existing faith (Rom. 4:11), and as such it has its necessary place, but it is not that of reception.
>> Part 4. The Value Of Justification (to be added)
 In Romans 3:25, διά, and the genitive case; Romans 1:17, ἐκ, and the genitive case; Romans 3:28, the dative.
 For a thorough treatment see Faith, by Bishop Moule of Durham.
 “Faith is an activity of the whole soul, of the intellect, the sensibility, and the will. There is an intellectual element in it; in order to trust we must know the person whom we trust, and know something about him. This is where the assent to truth comes in, or rather begins to come in. Then there is an element of feeling in faith; we cannot stand in this relation to another person without experiencing certain emotions respecting him, such as love, reverence, admiration, or the like. Finally, there is an element of will in faith, and this is the distinctive element. This is what makes faith a moral activity. There is choice in it. We may exercise it or abstain from it. There is always in true faith, a laying of our will, to an extent greater or less, into the keeping of another will. These three elements are not always present in the same proportion. Now one is more prominent, now another. But always in its deepest essence faith is a matter of the will, of free choice” (Stearns, ut supra, p. 451).
 Definition of Justification, Chapter 33.
 “Christian faith is the faith of a transaction. It is not the committing of one’s thought in assent to any proposition, but the trusting of one’s being to a being, there to be rested, kept, guided, moulded, governed, and possessed for ever. It gives you God, fills you with God in immediate, experimental knowledge, puts you in possession of all there is in Him, and allows you to be invested with His character itself” (Life of Bushnell, p. 192, seq.).
 See on Article 27.