From Got Questions:
Jesus is described as the author and perfecter, or finisher, of our faith in Hebrews 12:2. An author is an originator or creator, as of a theory or plan. The Greek word translated “author” in Hebrews 12:2 can also mean “captain,” “chief leader” or “prince.” Acts 3:15 uses the same word: “And killed the Prince of life, whom God hath raised from the dead; whereof we are witnesses” (KJV), while the NIV and ESV use the word “author” instead of “prince.” From this we can deduce that Christ is the originator of our faith in that He begins it, as well as the captain and prince or our faith. This indicates that Jesus controls our faith, steers it as a captain steers a ship, and presides over it and cares for it as a monarch presides over and cares for his people.
The Greek word translated “perfecter” in Hebrews 12:2 appears only this one time in the New Testament. It means literally “completer” or “finisher” and speaks of bringing something to its conclusion. Putting the two words together, we see that Jesus, as God, both creates and sustains our faith. We know that saving faith is a gift from God, not something we come up with on our own (Ephesians 2:8-9), and that gift comes from Christ, its creator. He is also the sustainer of our faith, meaning that true saving faith cannot be lost, taken away or given away. This is a source of great comfort to believers, especially in times of doubt and spiritual struggles. Christ has created our faith and He will watch over it, care for it, and sustain it.
It is important for us to understand that God in Christ is not only the creator and sustainer of our saving faith, but He is also the sustainer of our daily walk and the finisher of our spiritual journey. For if God in Christ is not the author of our new life, and if Christ is not the finisher and perfecter of our faith through the Holy Spirit’s indwelling power, then we are neither born again nor are we a true follower of Christ. “And I am sure of this, that he who began a good work in you will bring it to completion at the day of Jesus Christ.” “In him you also, when you heard the word of truth, the gospel of your salvation, and believed in him, were sealed with the promised Holy Spirit, who is the guarantee of our inheritance until we acquire possession of it, to the praise of his glory” (Philippians 1:6; Ephesians 1:13-14).
Nope, I did not author my faith; but then, did you check the context?
Heb 12:1 Wherefore seeing we also are compassed about with so great a cloud of witnesses, let us lay aside every weight, and the sin which doth so easily beset us, and let us run with patience the race that is set before us,
Heb 12:2 Looking unto Jesus the author and finisher of our faith; who for the joy that was set before him endured the cross, despising the shame, and is set down at the right hand of the throne of God.
Heb 12:3 For consider him that endured such contradiction of sinners against himself, lest ye be wearied and faint in your minds.
Heb 12:4 Ye have not yet resisted unto blood, striving against sin.
If by 'author' you mean 'decreed whatsoever comes to pass' then that would include becoming weary, fainting, and not resisting.