Philippians 2:12 gives us this instruction!
Therefore, my dear ones, as you have always obeyed [my suggestions], so now, not only [with the enthusiasm you would show] in my presence but much more because I am absent, work out (cultivate, carry out to the goal, and fully complete) your own salvation with reverence and awe and trembling (self-distrust, with serious caution, tenderness of conscience, watchfulness against temptation, timidly shrinking from whatever might offend God and discredit the name of Christ).
"Salvation" here is the Greek word "soteria", which means: rescue, safety, deliverance, preservation. This is concerning THIS life! We already have Eternal Life from the moment of our New Birth, alive in us. But we must "work out" that life, from the inside out, in order to have the benefits available to us in the here and now! "Work out" is the Greek word "katergazomai", which means: to perform, accomplish, achieve, to work fully, to finish. This "working out" involves studying the Word of God to find out just what belongs to us as born again children of the Living God! Then we must meditate on that Word until it becomes SO real IN us that no doubt from the enemy can affect us! Joshua 1:8 explains meditation and the benefits of it:
8 This Book of the Law shall not depart out of your mouth, but you shall meditate on it day and night, that you may observe and do according to all that is written in it. For then you shall make your way prosperous, and then you shall deal wisely and have good success. AMP
"Meditate" means to utter (speak), to ponder, to muse, to dream. Holy Spirit IN us is the ONE Who makes the Word real and alive. Meditation gives Him the avenue to get what is inside of us into our souls (mind, emotions and will) so that our understanding is enlightened and we can make right choices, expecting the results that the Word promises! Remember, God hides these things in His Word FOR us to find out! Only those who "follow on to know" will really learn and know. When we put this type of diligence into studying and learning the Word, THIS promise, from Philippians 2:13 is OURS!
[Not in your own strength] for it is God Who is all the while effectually at work in you [energizing and creating in you the power and desire], both to will and to work for His good pleasure and satisfaction and delight.
AMEN! The CHOICE is ours and the WORK is HIS! HALLELUJAH! Thank You, JESUS! Here is Hillsong with "I Live To Know You":
Shalom in Him!