Because. Giving the ground of the statement that Christians received new and richer gifts of grace: the ground being that the law of Moses was a limited and narrow enactment, while Jesus Christ imparted the fullness of grace and truth which was in Him (Joh 1:14). Compare Rom 4:15; Rom 10:4; Gal 3:10.
Was given (ἐδόθη)
A special gift serving a special and preparatory purpose with reference to the Gospel: the word being appropriate to “an external and positive institution.”
By Moses (διά)
Literally, through. See on by Him, Joh 1:3.
Grace and truth came (ἐγένετο)
Came into being as the development of the divine plan inaugurated in the law, and unfolding the significance of the gift of the law. They came into being not absolutely, but in relation to mankind. Compare 1Co 1:30, where it is said of Christ, He was made (properly, became, εγενήθη) unto us wisdom and righteousness, etc. Note the article with grace and truth; the grace and the truth; that which in the full sense is grace and truth. Grace occurs nowhere else in John, except in salutations (2Jo 1:3; Rev 1:4; Rev 22:21).
The Being who has been present in the Evangelist's mind from the opening of the Gospel is now first named. The two clauses, “the law was given,” “grace and truth came,” without the copula or qualifying particles, illustrate the parallelism which is characteristic of John's style (see on Joh 1:10).