If power is made perfect in weakness -- and we have it on good authority that it is -- then strength always leaves power imperfect.
St. Paul was bothered by his thorn in the flesh, and so came to understand that when he was weak in himself, then he was strong in Christ.
Suppose, though, we are strong enough in ourselves, at least for day to day living. (Though whether any of us are actually strong enough in ourselves, and not merely deceiving ourselves about what discipleship demands of us, is another question.) Then, even if we make it through this life without collapsing, we'll still have failed to be the channels of God's power in the world that He intends us to be.
It seems that we can be strong in ourselves, or strong in Christ, and Christ leaves the choice to us. Pray for the grace to make the right choice!