These nouns denote the capacity to act or work effectively. Strength refers especially to physical, mental, or moral robustness or vigor: “enough work to do, and strength enough to do the work” (Rudyard Kipling). Power is the ability to do something and especially to produce an effect: “I do not think the United States would come to an end if we lost our power to declare an Act of Congress void” (Oliver Wendell Holmes, Jr.) Might often implies abundant or extraordinary power: “He could defend the island against the whole might of the German Air Force” (Winston S. Churchill). Energy refers especially to a latent source of power: “The same energy of character which renders a man a daring villain would have rendered him useful to society, had that society been well organized” (Mary Wollstonecraft). Force is the application of power or strength: “the overthrow of our institutions by force and violence” (Charles Evans Hughes).
You gave me the strength to take a step I wouldn't have otherwise.
After Dad died, there was neither time nor emotional strength for a pet.
So also, owing to bodily and mental health and strength, we may be continually cheered by a like but more normal and natural society, and come to know that we are never alone.
Before the battle of Borodino our strength in proportion to the French was about as five to six, but after that battle it was little more than one to two: previously we had a hundred thousand against a hundred and twenty thousand; afterwards little more than fifty thousand against a hundred thousand.
He mustered his last remaining strength, took hold of his left hand with his right, and reached the bushes.