One of the most significant mentors in my life spiritually used to say to those whose lives she so dramatically impacted, “It’s not that you cannot; it’s that you will not.” She wasn’t trying to tell us to simply “will” ourselves through situations for Christ. She was trying to remind us that a surrendered will to the will of God was part of a life lived by faith.
Philippians 4:13 says that “We can do all things through (in) Christ who (continuously) strengthens us.” There’s nothing that God ever calls us to do that Jesus isn’t prepared to do through us, but without abandonment to His will and confidence in His ability, the divine outflow of His grace is restricted. Faith involves a choice, and that choice is to say yes, stepping out trusting in His faithfulness. The only real issue is whether something is or is not God’s will for us. It is missing the mark to do less than what God wants or to do more than what God wants, but if we discern that a certain thing is God’s will for us (which is the easiest thing in the world to discern, by the way – I don’t know why we make it so complicated), then we can be certain that in choosing God’s will, the illimitable resources of Christ will be at our disposal, because again, what He requires of us, He’s always prepared, because of our union with Him, to perform through us. All of God’s demands are actually promises of His adequacy. Living from Christ is being set free from the “I can’t’s” that so deny us from participating in His supernatural life.