Every one of us is necessary to every one else. You say, "That brother is so bad"; but I say, "He is necessary to you." You say, "Oh! but he troubles me so much; there is this thing and that thing about him." Well, that is the very thing you need. Do you think that there is a single thing that happens that is not necessary to us? This world is God's training ground, and God sees to it that there is everything to exercise us, and even to rub us the wrong way, in order that He might have the opportunity to strengthen us and make us faithful.