This may be one of the most used and yet least well-used one-liners in all the New Testament. For me, it brings back memories of growing up in Christian summer camps, where sweaty teenage guys are trying to push through their final bench rep with a dude standing over them, yelling, "You can do ALL things through him who strengthens YOU, bro!"
But the Phillips translation gets closer to the actual dynamism of the Greek used: "I am ready for anything through the strength of the one who lives within me."
And here's a most exact wording: "I am powerful for all things in the One in-strengthening me." And the really fun thing? The "strengthening" in that conjunctive word is the same word from which we get the English word "dynamite."
Friends, you are powerful for all things in the One, Jesus, who, by the power of His indwelling Holy Spirit, is standing over the dynamite box with both hands on the detonator. That was the unconquerableness of Paul, of Peter, of the spirits of those we call the Early Church! And that is the truth of the outlook available to you as you begin this or any day of your life! Oh, may we walk in the dynamite-power that is dangerously ready to ignite within us all day today!