John 1:14-18 The Word Made Flesh

1:14 And the Word was made flesh, and dwelt among us, (and we beheld his glory, the glory as of the only begotten of the Father,) full of grace and truth.

And the Word was made flesh — That very person who was in the beginning-who was with God-and who was God, John 1:1, in the fulness of time became flesh-became incarnated by the power of the Holy Ghost, in the womb of the virgin.
And dwelt among us — και εσκηνωσεν εν ημιν, And tabernacled among us: the human nature which he took of the virgin, being as the shrine, house, or temple, in which his immaculate Deity condescended to dwell.

1:15 John bare witness of Him, and cried, saying, This was He of whom I spake, He that cometh after me is preferred before me: for He was before me.

He appeals to what he had said at the beginning of his ministry, when he had directed them to expect one that should come after him, whose forerunner he was, and never intended any other than to lead them to Him, and to prepare his way.
Was before me — Speaking by the prophets, and warning your fathers to repent and return to God, as I now warn you;

1:16 And of His fulness have all we received, and grace for grace.

And of His fulness — Of the plenitude of His grace and mercy, by which He made an atonement for sin; and of the plenitude of His wisdom and truth, by which the mysteries of heaven have been revealed.
We have received grace for grace -- Our receivings by Christ are all summed up in this one word, grace; we have received kai charin—even grace.

1:17 For the law was given by Moses, but grace and truth came by Jesus Christ.
The law of Moses, however excellent in itself, was little in comparison of the Gospel: as it proceeded from the justice and holiness of God, and was intended to convict men of sin, that the way of the Gospel might be the better prepared, it was a law of rigor, condemnation, and death: Romans 4:15; 2 Corinthians 3:7-8. 

It was a law of shadows, types, and figures: Hebrews 10:1, and incapable of expiating sin by its sacrifices: Romans 8:3; Hebrews 10:11. 

But Christ has brought that grace which is opposed to condemnation: Romans 5:15; Romans 8:1; and He is Himself the spirit and substance of all those shadows: Colossians 2:19; Hebrews 10:1.

Jesus Christ — JESUS the CHRIST, the Messiah, or anointed prophet, priest, and king, sent from heaven.

1:18 No man hath seen God at any time; the only begotten Son, which is in the bosom of the Father, He hath declared Him.

No man hath seen God at any time — Moses and others heard His voice, and saw the cloud and the fire, which were the symbols of His presence; 

but such a manifestation of God as had now taken place, in the person of Jesus Christ, had never before been exhibited to the world.

No man hath seen God at any time - Who can look on the sun? What mind can look on God? But Christ does not hide the Father; He manifests Him.
He hath declared God to us, whom no man hath seen at any time. This was the grace and truth which came by Christ, the knowledge of God and an acquaintance with Him.