Justification is by faith

Rom 4:16  This is why the fulfillment of God's promise depends entirely on trusting God and His way, and then simply embracing him and what he does. God's promise arrives as pure gift. That's the only way everyone can be sure to get in on it, those who keep the religious traditions and those who have never heard of them. 
For Abraham is father of us all. He is not our racial father--that's reading the story backwards. He is our faith father.

 Romans 4:16

Therefore - In view of the course of reasoning which has been pursued. We have come to this conclusion.
It is of faith - Justification is by faith; or the plan which God has devised of saving people is by faith, Rom_3:26.
That it might be by grace - As a matter of mere undeserved mercy. If people were justified by law, it would be by their own merits; now it is of mere unmerited favor.
To the end - For the purpose, or design.
The promise ... - Rom_4:13.
Might be sure - Might be firm, or established. On any other ground, it could not be established. If it had depended on entire conformity to the Law, the promise would never have been established, for none would have yielded such obedience. But now it may be secured to all the posterity of Abraham.
To all the seed - Rom_4:13.
Not to that only - Not to that part of his descendants alone who were Jews, or who had the Law.
But to that ... - To all who should possess the same faith as Abraham. The father of us all. Of all who believe, whether they be Jews or Gentiles.

Rom 6:3  Or didn't you realize we packed up and left there for good? That is what happened in baptism. When we went under the water, we left the old country of sin behind; when we came up out of the water, we entered into the new country of grace--a new life in a new land! That's what baptism into the life of Jesus means. 

Rom 6:4  When we are lowered into the water, it is like the burial of Jesus; when we are raised up out of the water, it is like the resurrection of Jesus. 

Rom 6:11  From now on, think of it this way: Sin speaks a dead language that means nothing to you; God speaks your mother tongue, and you hang on every word. You are dead to sin and alive to God. That's what Jesus did. 

Romans 7:5  While we were living under the influence of our corrupt nature, sinful passions were at work throughout our bodies. Stirred up by Moses' laws, our sinful passions did things that result in death. 

For when we were in the flesh,.... This respects not their being under the legal dispensation, the Mosaic economy; which lay greatly in meats and drinks, and divers washings, and carnal ordinances, such as regarded the flesh chiefly; so their meats and drinks concerned the body; their ablutions and washings sanctified to the purifying of the flesh; their circumcision was outward in the flesh; the several rituals of the law consisted in outward things, though typical of internal and spiritual ones; hence those that trusted in them trusted in the flesh: but to be "in the flesh" stands opposed, Rom_7:8; to a being "in the spirit"; whereas there were many under that legal and carnal dispensation who were in the spirit, and had the Spirit of God, as David and others; besides, the apostle must be thought to use the phrase in such a sense, as to include all the persons he is speaking of and writing to, who were both Jews and Gentiles, for of such the church at Rome consisted; and the sense is this, "for when we", Jews and Gentiles, who are now believers in Christ, "were" formerly, before our conversion to, and faith in Christ, "in the flesh", that is, in a corrupt, carnal, and unregenerate state and condition; in which sense the word "flesh" is frequently used in the next chapter: now not all such who have flesh, sin, or corrupt nature in them, must be reckoned to be in the flesh, for there is a difference between flesh being in persons, from which none are free in this life, and their being in the flesh; nor all such who commit sin, or do carnal things at times, for there is not a just man that doth good and sinneth not; but such who are as they were born, without any alteration made in them by the Spirit and grace of God; who have nothing but flesh in them, no fear of God, nor love to and faith in Christ, nor any experience of the work of the Spirit of God upon their souls; no true sight and sense of sin, nor any spiritual knowledge of salvation by Christ; in whom flesh is the governing principle, whose minds and principles are carnal, and their conversation wholly so; yea, persons may be in the flesh, in an unregenerate state, who may abstain from the grosser immoralities of life, and even make a profession of religion: now such these had been the apostle is speaking of and to, and tells how it was with them when in this state; 

the motions of sins which were by the law, did work in our members to bring forth fruit unto death: by "the motions of sin" are meant, the evil passions and affections of the mind, the lusts of the heart, sinful desires, evil thoughts, the imaginations of the thoughts of the heart, the first motions of the mind to sin: these "were by the law"; not as the efficient cause of them, that neither produces nor encourages them; it is holy, just, and good, requires truth in the inward parts, and not only forbids the outward acts of sin, but even covetous desires, and lustful thoughts: no, these inward motions of sin arise from a corrupt heart and nature; are encouraged and cherished by the old man that dwells there; and men are enticed by Satan to a compliance with them. Some think that the meaning of the phrase is, that these secret lusts of the heart are made known by the law, as in Rom_7:7, so they are, but not whilst a man is in the flesh, or in an unregenerate state, but when he comes to be wrought upon powerfully by the Spirit of God, who makes use of the law to such a purpose: but the true sense of it is, that these motions of sin are irritated, provoked, and increased, through the law's prohibition of them; which is not to be charged as a fault on the law, but to be imputed to the depravity and corruption of man; who is like to one in a burning fever, very desirous of drink, who the more it is forbid, the more eager is he of it; or like a mighty torrent of water, which rises, rages, flows, and overflows, the more any methods are taken to stop its current; or like a filthy dunghill, which when the sun strikes powerfully on it, it exhales and draws out its filthy stench; which nauseous smell is not to be imputed to the pure rays of the sun, but to the filthiness of the dunghill: these motions of sin are said to "work in our members"; in the members of our bodies, which these sinful affections of the soul make use of to put them into action, and so they bring forth fruit; very evil fruit indeed, for nothing else can be expected from such an evil tree as the corrupt nature of man is: and this fruit is "unto death": deadly fruit, worthy of death, and would issue in eternal death, if grace did not prevent: the rise, beginning, motion, progress, and issue of sin, are most exactly and beautifully described, agreeably to this account here, by the Apostle James, Jam_1:13.