Jesus is the reflection of God's glory and the exact likeness of God's being. Jesus is the personification of God's character and the expressed image of God's person. He upholds all things by the word of His power. After He had cleansed us from our sins, He received the highest position, sat down on the right hand of the Majesty on high, who is our Father in heaven.
John 1:17 (King James Version) says "For the law was given by Moses, but grace and truth came by Jesus Christ."
Yes, no doubt the proposition "by" or "through" in Greek, dia (dee-ah') is a primary preposition denoting the channel of an act and Jesus was that channel. John 14:6 (King James Version)
says "Jesus saith unto him, I am the way, the truth, and the life: no man cometh unto the Father, but by me." Jesus as grace of God. As we know, grace is "the kindness and love of God our Saviour toward man. . . " Timothy 3:4.