This is very explicit all throughout the text...many quote Phillip. 2-13 but ignore verse 12.....
Philippians 2-12,13
It’s the influencing power of grace combined with man’s faith, for we are workers together with God.
The principles of man working together with God are plastered all over the text from Genesis to Revelation.
Here is an excellent example given by Paul in the letter to the Philippians.
2-12 Wherefore, my beloved, as ye have always obeyed, not as in my presence only, but now much more in my absence, workout you own salvation with fear and trembling (fear of God; in that it’s a fearful thing to fall in the judgement hands of the living God, for the wrath of God remains on the children of disobedience)
13 “for it is Him that worketh (energeo) in you both to will and to do His good pleasure”