Here is a summary of Romans chapter 5 with a Bible study and commentary.
Romans 5:1-2 “Therefore, since we have been justified by faith, we have peace with God through our Lord Jesus Christ. Through him we have also obtained access by faith into this grace in which we stand, and we rejoice in hope of the glory of God.”
What is the “therefore” there for? The “therefore” always points back to what was previously said and in this case, Paul  had just written that “it was counted to him’ were not written for his sake alone, but for ours also. It will be counted to us who believe in him who raised from the dead Jesus our Lord, who was delivered up for our trespasses and raised for our justification” (Rom 4:23-25) so this is why he says “we have been justified by faith” therefore or because of this “we have peace with God through our Lord Jesus Christ” for it is “through him we have also obtained access by faith into this grace” and that’s how we can stand before God and why “we rejoice in the hope of the glory of God.”
Rom 5:3-5 “Not only that, but we rejoice in our sufferings, knowing that suffering produces endurance, and endurance produces character, and character produces hope, and hope does not put us to shame, because God’s love has been poured into our hearts through the Holy Spirit who has been given to us.”
By this hope of the glory of God we can rejoice in our sufferings because it “produces endurance” and this endurance “produces [godly] character” when this “produces hope.” This is only possible though “because God’s love has been poured into our hearts through the Holy Spirit.” Therein lays our hope.
Romans 5:6-8 “For while we were still weak, at the right time Christ died for the ungodly. For one will scarcely die for a righteous person—though perhaps for a good person one would dare even to die but God shows his love for us in that while we were still sinners, Christ died for us.”
Before we were saved, “while we were still weak” the perfect timing of Christ’s death for us, “the ungodly,” shows or proves “his love for us that while we were still sinners” it was “Christ [Who] died for us.” That’s why grace is so amazing…He died for us not because we had come out of sin but even while we were still sinners and still sinning!
Romans 5:9-10 “Since, therefore, we have now been justified by his blood, much more shall we be saved by him from the wrath of God. For if while we were enemies we were reconciled to God by the death of his Son, much more, now that we are reconciled, shall we be saved by his life.”
We were justified by His blood but more, we “shall be saved by him from the wrath of God” and it’s called the good news because “while we were enemies we were reconciled to God by the death of his Son.” Imagine dying for your spouse or your children or even a friend. Now imagine dying for an enemy who had caused you to be crucified. Can you even imagine a greater love? We were reconciled by His blood and saved from the wrath; a wrath we deserved taken by Him Who didn’t. This is how we “received reconciliation” (Rom 5:10).
Romans 5:12, 16 “Therefore, just as sin came into the world through one man, and death through sin, and so death spread to all men because all sinned, the free gift following many trespasses brought justification.”
The Bible teaches that we were all born sinners and conceived in sin as David writes “Behold, I was brought forth in iniquity, and in sin did my mother conceive me” (Psalm 51:5) but again, the good news is that “the free gift following many trespasses brought justification” through His blood.
Romans 5:17 “For if, because of one man’s trespass, death reigned through that one man, much more will those who receive the abundance of grace and the free gift of righteousness reign in life through the one man Jesus Christ.”
Through this one man’s trespass or sin (Adam) death came  even though God warned Adam that “for in the day that you eat of it you shall surely die” (Gen 2:17b). Adam did die; not immediately but eventually because the wages of our sins is death (Rom 6:23a). Wages are paid for services rendered and the rendering of the wages we earned was death but the free gift of God allows us to receive eternal life (Rom 6:23b) and it is through, once again, the “free gift of righteousness…through the one man, Jesus Christ.”
Romans 5:18-19 “Therefore, as one trespass led to condemnation for all men, so one act of righteousness leads to justification and life for all men. For as by the one man’s disobedience the many were made sinners, so by the one man’s obedience the many will be made righteous.”
It only took one sin to lead Adam into condemnation and this condemnation passed unto all men but then the one act of righteousness led “to justification and life for all men.” That one act was displayed at the cross and his life’s blood justified us and by this “one man’s obedience the many will be made righteous.”
The Book of Roman’s is among my favorites because it shows us the inability of mankind to save himself. It frequently points to the only means of justification and that is through the blood of Jesus Christ, shed for all who believe in Him and that belief brings the hope of glory and eternal life with Christ.
Take a look at this related reading: Romans Commentary, Summary and Key Verses 
Resource – Scripture quotations are from The Holy Bible, English Standard Version® (ESV®), copyright © 2001 by Crossway, a publishing ministry of Good News Publishers. Used by permission. All rights reserved.