Devote means to give to. If you devote yourself to jump-roping, you might be found in your driveway every free moment of the day practicing.
Nuns and priests are said to devote their lives to God. A knight in shining armor devotes himself to his lady. If you devote as much energy to your school work as you do to your hair, your grades should improve. If our country devoted to education even half of the resources we pour into defense, we could eliminate poverty.