You know how when we eat salad and fruit, our body gets strong to run and play, right? And when we only eat junk, our tummy hurts.
The Bible says obeying God and trusting Him is like taking a "Super Vitamin." When we do something wrong (lie, fight), we feel a bad feeling inside, our heart tightens, we get a nervous stomachache. But when we trust God and do the right thing, we feel a good joy and energy, like we just took the best medicine in the world!