Romans 7:4 — Wherefore, my brethren, ye also are become dead to the law by the body of Christ; that ye should be married to another, even to Him who is raised from the dead, that we should bring forth fruit unto God.
body of Christ = His death, possible because He took on a human body. Forasmuch then as the children are partakers of flesh and blood, he also himself likewise took part of the same; that through death He might destroy him that had the power of death, that is, the devil (Hebrews 2:14).
By Christ's death, believers were put to death to the law.
This verse parallels verse three except that it isn't the "first husband" (the law) that dies, but our former selves. Or, to put it another way, our covenant to the law died.
In the Old Testament we find the death of the Law clearly typified. Recall how, in the face of Israel's flagrant disobedience, God said to Moses: Let them make Me a sanctuary that I may dwell among them (Exodus 25:8). Would not this be a breach of the covenant He had just made with them, and which they had ratified? They had not "obeyed" His voice "indeed." Already they were about to desecrate the very first commandment. But did you notice the first article of furniture God commanded Moses to make for the tabernacle? The words are: And they shall make an ark … (Exodus 25:10). But what is an ark? … The very same work here rendered "ark" is translated "coffin" in the last verse of Genesis. This harmonizes with the use to which this ark was put, for in Exodus 25 the commandment is given:
And thou shalt put into the ark the testimony which I shall give thee. And thou shalt make a mercy seat of pure gold … And thou shalt put the mercy seat above the ark; and in the ark thou shalt put the testimony that I shall give thee. And there I will meet with thee, and I will commune with thee from above the mercy seat (Exodus 25:16-17, 21-22).
Beautiful type! The Law had hardly been given when God said: "Put it in a coffin and cover the coffin with a mercy seat (to be sprinkled with the atoning blood — Leviticus 16:14-15), and there from the mercy seat, I will meet with you." — C.R. Stam, The Epistle of Paul to the Romans, pgs. 161-162.