There is only one way to find out if something is an idol in your life: let it be taken away. Then, if you really mourn for it, you know that your heart has been given over to an idol. For example, if God took away your food, how would you react? God weighs the motives of the heart.
Will you be drained if you give ALL of your heart to God? It is a miracle—you will discover that you have even more time and energy if you put God above all. However, if you worship something above God (football and basketball, computers and cars, clothes and social climbing, chocolate and desserts, children and careers) you will feel drained, lethargic, worn out, emotionless, empty. You will not have energy to love your spouse, children, or friends.
Everyone is religious and everyone adores something, but one drains and one gives back. A false god can give nothing back. The One True God owns it all and does not need your love or time or energy, so He just gives it right back!