Matthew 11:28 Come unto me, all ye that labour and are heavy laden, and I will give you rest. 29 Take my yoke upon you, and learn of me; for I am meek and lowly in heart: and ye shall find rest unto your souls. 30 For my yoke is easy, and my burden is light.
Looking at Romans 5:21, sin can only produce death. Righteousness can only produce grace and life. Here in Romans 5 Paul is telling us the how and the when of our justification. It is by the righteousness earned by Jesus Christ. This is the righteousness of God. It is not the righteous character of God, but is that righteousness earned by Christ and accepted by God and imputed to us. That is the process by which we are justified. We are made right with God by the earned righteousness of Christ. That is grace. The unmerited favor of God whereby we find our justification in the eyes of God. The one and only condition of this is the obedience unto death of Jesus Christ. We do not see here in Romans 5 or anywhere else a condition fulfilled by man that makes him just before God. Our justification is Christ. We rest in Him. If we do not rest then our works are unto death.
Romans 7:5 For when we were in the flesh, the motions of sins, which were by the law, did work in our members to bring forth fruit unto death.
John 6:63 It is the spirit that quickeneth; the flesh profiteth nothing: the words that I speak unto you, they are spirit, and they are life.
The flesh profits nothing. In fact, by our flesh comes death. Anything you think you can do to commend yourself to God earns death. If a condition was placed that you could perform you would have to do that in perfection, not only in deed, but in thought. We cannot obtain a right standing before God by ourselves. Paul is showing us that Christ did this for us.
Romans 6:17 But God be thanked, that ye were the servants of sin, but ye have obeyed from the heart that form of doctrine which was delivered you.
The doctrine delivered to us is the doctrine of rest. We rest in what He has done. There is no work to add. Our salvation is completed altogether outside of anything that we have done. It is outside of ourselves. A sinner cannot add to his salvation. To not see that salvation is finished and complete in Him is to not understand the cross. It is to not rest in Him. It is not an issue of timing; it is to miss what was accomplished when He cried it is finished. It is what God the Father did with what Christ completed.
John 6:64 But there are some of you that believe not. For Jesus knew from the beginning who they were that believed not, and who should betray him. 65 And he said, Therefore said I unto you, that no man can come unto me, except it were given unto him of my Father.
If that rest is not given from above you will never find it. In contrast we see in John 10:
John 10:27 My sheep hear my voice, and I know them, and they follow me: 28 And I give unto them eternal life; and they shall never perish, neither shall any man pluck them out of my hand.
His sheep hear His voice. His voice is the truth, it is the word of God. The word of God will be heard by the sheep and believed. They will find the rest within that word.
John 10:26 But ye believe not, because ye are not of my sheep, as I said unto you.
There are those who do not believe because they were not meant to believe. They will not find the rest of the Savior. They may continue to seek out that which they feel will please God. The only rest for us is in the knowledge that He has come, and His work is finished. Rest in the justification that comes by that earned righteousness of Christ imputed to those for whom He came. God could require nothing in addition to His finished work as it was sufficient to save and did save. Not one drop to little or one drop too much of His blood was shed to save His sheep. Rest in that completed salvation. Rest in Him.
Faith is a persuasion that what God has said is true. We see this truth preached to Abraham all those years ago and to us today. It is the truth of a salvation that came by the righteousness earned by Jesus Christ. The Holy Spirit in time brings this message to our hearts in connection with the hearing of the gospel. By this faith we rest with peace toward God in that completed justification. Justification completed outside of any decision we could make. Completed when righteousness was earned and imputed at and by the cross of Christ.