[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 – Philippians 2:13 AMPC.
If I could summarize Christianity, I’d say it’s about the heart and a heart surrendered to GOD and the work GOD wants to do in and through each and everyone of us. Salvation is God’s idea, He’s the One that called us into His marvelous light with a plan and a purpose for each of us which will ultimately bring glory to His name (1 Peter 2:9). On our own we can do absolutely nothing for GOD and in the Kingdom of GOD. When we are born again GOD gives us a new heart and a new spirit and He causes us to walk in obedience to His Word (Ezekiel 37:26-27).
The LORD tells us that our righteousness is as filthy rags in Isaiah 64:6 so none of us can actually boast about anything. If we are to please GOD, anything we do for GOD or in the name of GOD has to be done through His Holy Spirit, it is not by power nor by might (Zechariah 4:6). I believe that is why GOD uses broken people who have nothing to offer but their hearts. He chose the foolish things to shame the wise and the weak things to shame the mighty, He uses the despised things that He may put to shame the things that are so that no flesh should glory in His presence (1 Corinthians 1:26-29).
Let us engage our hearts and allow GOD to work in us to do His will and His desire that we may do what is pleasing to Him. GOD is after a people that know that they have nothing to offer but their hearts. So we should offer ourselves as living sacrifice with our hearts fully engaged and surrendered to GOD and leave the rest to Him.
If we are to please GOD, anything we do for GOD or in the name of GOD has to be done through His Holy Spirit, it is not by power nor by might; this is why GOD uses broken people who have nothing to offer but their hearts