Hebrews 12:1-2 (ESV)
Therefore, since we are surrounded by so great a cloud of witnesses, let us also lay aside every weight, and sin which clings so closely, and let us run with endurance the race that is set before us,  looking to Jesus, the founder and perfecter of our faith, who for the joy that was set before him endured the cross, despising the shame, and is seated at the right hand of the throne of God.
Jesus the founder and perfecter of our faith. We could understand this in at least two ways and both would be correct. He is the founder and perfecter of the faith in that he completed the Old Testament and perfected it with the New. He fulfilled the prophecies and the law.
Coincidently it is the fulfillment of the law we celebrate today in the circumcision of Christ. It is a special day that really deserves more attention than it gets. Today marks the first day in which Jesus shed blood for us sinners. With his circumcision he put himself under a law he did not need to, and made a down payment for our sins with the bloodshed that day. Everyone wants to concentrate on the naming of Christ. It gives them a chance to discuss his deity etc. It is also a bit more politically correct. Circumcision isn’t a topic to be discussed in polite company, and makes most men squirm a bit. The single verse in Luke that provides the reading for this day(Luke 2:21) is perhaps the best single verse illustration of the two natures in Christ, divine and human, there is in all the Bible. Here his divinity is shown in the name, the humanity in the cut around his manhood, and the blood he shed.
But Jesus is not just the founder and perfecter of our faith in that he fulfilled the prophecies but also in that he perfects our weak faith. We keep our eyes on Jesus, for he is the one who helps our unbelief.