This verse is sometimes explained as representing the Old Covenant being replaced by the New, as though it meant one kind of grace instead of another kind. But if that is what John had in mind, he would doubtless have written “… grace in place of law already given” – especially as we see in the very next verse: “For the law was given through Moses; grace and truth came through Jesus Christ” (John 1:17).
The meaning of “grace” itself is straightforward. As is often said, while “mercy” refers to our not getting what we deserve, “grace” refers to our getting what we do not deserve – the many blessings God pours out upon us. But what does “grace in place of grace” mean?
Fortunately, the meaning of John’s statement is fairly easy to determine. In writing that we have received “grace in place of grace” (emphases added here and below), the apostle is not contrasting two different things, but two (or more) things of the same kind. In the Greek in which the New Testament was written the expression is literally “grace for grace” (see for example, Matthew 5:38, “an eye for an eye”) meaning “grace in place of grace” or “grace on top of grace.” The English Standard Version translates the verse in this way with the wording “grace upon grace.”
This implies not a change of grace, but an addition to the grace we originally received – an ongoing gift of God’s grace. In this sense, the word grace is almost synonymous with blessings. That is what John means by “Out of his fullness we have all received grace …” And we should not forget that John makes this comment directly after telling us that the Son of God came from the Father “… full of grace and truth” (John 1:14). That is the fullness from which, vs. 16 tells us, we receive God’s blessing of grace.
But John’s main point is that God does not simply grant us his grace when we initially turn to him (John 1:12). He continues to grant that grace to us in an ongoing manner throughout our Christian lives (John 1:16).
Despite heavy Greek and Roman influences, the Jewish culture of the New Testament period was still essentially a Semitic one in which the repetition of a word in Hebrew or Aramaic (the commonly spoken language of Judea at that time) was used to indicate the “superlative” degree of comparison. In other words, just as we find “pits, pits,” meaning many pits in Genesis 14:10, so John’s use of “grace for grace” not only literally meant “grace upon grace” but also conveyed, to John’s 1st century Jewish readers, the underlying concept of “much grace.”
So John 1:16 is not referring in any way to the Old and New Covenants described in the Bible. It simply stresses God’s full and ongoing blessing and the outpouring of his gift of grace to us in a continuous manner. Put simply, God not only blesses us, he continually and constantly blesses us with his grace.