That phrase you are referring to is in the book of 1 Timothy.  1 Timothy 6:12 says, “Fight the good fight of faith, LAY HOLD ON ETERNAL LIFE, whereunto thou art also called, and hast professed a good profession before many witnesses.”  This verse is rich with precious truth.  Let’s examine it briefly.

FIGHT THE GOOD FIGHT OF FAITH – As believers on the Lord Jesus Christ, we have more important business to do than to mind the things of this world.  Our lives are in a constant state of warfare.  We are soldiers for the Lord and should not entangle ourselves with the things of this world.  We are exhorted in Galatians 5:1 to, “Stand fast therefore in the liberty wherewith Christ hath made us free, and be not entangled again with the yoke of bondage.”  We are heavenly people and should behave as such.  This good fight is the Christian faith and how we should earnestly and continuously fight or contend for it.  We read in Jude 3, “Beloved, when I gave all diligence to write unto you of the common salvation, it was needful for me to write unto you, and exhort you that ye should EARNESTLY CONTEND FOR THE FAITH which was once delivered unto the saints.”  The Apostle Paul would say of himself in 2 Timothy 4:7, “I have fought a good fight, I have finished my course, I have kept the faith.” 

LAY HOLD ON ETERNAL LIFE – This does not mean we must work for our salvation.  Neither does it mean we must struggle to maintain our salvation.  Ephesians 2:8-9 makes it very clear, “For by grace are ye saved through faith; and that not of yourselves: it is the gift of God: Not of works, lest any man should boast.”  Salvation is a gift from God, given to us through our trusting in the Lord Jesus Christ as our savior.  We cannot work to earn it, and we do not have to work to keep it.  It means we are to seize or take hold of the truth of the eternal life that we have in Christ.  We have the assuring words of Christ, Himself, in John 10:27-29 saying, “My sheep hear my voice, and I know them, and they follow me: And I give unto them ETERNAL LIFE; and they shall NEVER PERISH, neither shall any man pluck them out of my hand. My Father, which gave them me, is greater than all; and no man is able to pluck them out of my Father’s hand.” This life, this crowning achievement, belongs to us as believers on the Lord.  We have eternal life and shall never perish!  We read in James 1:12, “Blessed is the man that endureth temptation: for when he is tried, he shall receive THE CROWN OF LIFE, which THE LORD HATH PROMISED TO THEM THAT LOVE HIM.”

WHEREUNTO THOU ARE ALSO CALLED – Ah, this refers to God’s effectual and sovereign call to salvation.  One of scriptures’ greatest, most comforting truths is that the Lord works in our hearts and draws us to Himself in order for us to be saved.  Romans 8:29-30 tell us, “For whom he did foreknow, he also did predestinate to be conformed to the image of his Son, that he might be the firstborn among many brethren. Moreover whom he did predestinate, them HE ALSO CALLED: and whom he called, them he also justified: and whom he justified, them he also glorified.”

HAST PROFESSED A GOOD CONFESSION BEFORE MANY WITNESSES – This good confession is evidence of the work of the Lord in our hearts to draw us to Himself.  Perhaps this refers to Timothy’s public baptism, which is a wonderful profession to the world of the new life we have in Christ.  After baptism, we are exhorted to “walk in newness of life” (Romans 6:4), evidencing the eternal life we have in Christ.

Once more, in this chapter does the Apostle mention our laying hold on eternal life.  1 Timothy 6:19 says, “Laying up in store for themselves a good foundation against the time to come, that they may LAY HOLD ON ETERNAL LIFE.”  May we who truly know the Lord Jesus as our savior, learn to fight the good fight of faith and to lay hold on eternal life!  (CC)  (660.4)