So give yourselves humbly to God. Resist the devil and he will flee from you. (James 4:7)
Give yourself to the right stuff and resist the wrong stuff - you will be surprised how much your strength grows! Those who engage in resistance training will remind you of several things. First, your own body can be the very thing you begin to use as a means of building strength into your muscles. You see, your body acts as a 'resistance' - it provides the force to build muscle. Don't believe me? While you are there right now, lift your leg using only the strength of your leg/abdomen muscles and hold it there for two minutes. Did you make it? Your own body's weight was being acted upon by the resistance force known as gravity and your body likely began to feel the strength of gravity's pull! This is a basic illustration of how resistance is actually helping us build 'muscle' over time.
Now, if we want to build 'muscle' of any sort, we have to concentrate on that which we want to 'build'. We wouldn't want to just focus on our upper arms at the expense of our shoulders, chest, lower arms, and even our hands. Why? Upper arm strength alone won't help us open that jar of pickles! We need to build all the muscles equally. In a similar manner, we need to build the 'spiritual muscles' we need to continually resist the devil's pull in life. Temptation is aimed at our weak muscles! It isn't aimed at the places we are already very strong. So, rob temptation of it's strength! Resist it a little more each time and see how much strength becomes your own in the process! Just sayin!