But if the Lord was going back to His Father's House--the place which was always His home--He was not willing to go alone. He might have gone back at any time, but if He would have those who could neither cleanse nor clothe themselves, who were sinful and unfit for that Home of love and light, He must go by the way of death, giving up His own life, that He might make them ready to dwell with Him in His Father's house; so that when He said, "I go to prepare a place for you," He, the Son of God, in His wonderful love, was going to do that which alone could make anyone fit to enter there, and be at home for evermore. But then we sometimes go on as if we were to live in this world for ever, and do not come to Him who says, "I am the way." Or perhaps we think we can make ourselves ready by trying to be good--forgetting that the One who is Himself the Truth said, "The Son of Man is come to seek and to save that which was lost," and that if the Lord is preparing a place, He wants a prepared people. But we were speaking about the way in which God, when He made this world in which we live, prepared it for the creatures to whom He would give it to be their dwelling-place; and especially of the globe of air with which He has surrounded the earth--that wonderful ocean of air in which we live and move, just as the fish live and move in their ocean of water. Let us see if we cannot learn something more about the atmosphere. But first of all let me ask, What can you tell me about it? "You cannot see the air; you can feel it, and often hear it." Yes, indeed we can. How delightfully fresh it comes to us as we swing, or when we are driving fast, or sailing; and how terrible its force is when the stormy wind rushes past, driving everything before it! It is then we can understand that the gentle air, which yields to the slightest touch, may be a very mighty power indeed. And now I am going to tell you something about the air which may surprise you. We often say of a thing that it is "as light as air"; but air is not really light, it is so heavy that it would press upon us and crush us, just as a great hammer might crush your little finger, only that this heavy weight of air presses quite evenly everywhere all through our body, within and without, upward as well as downward, and yields at once when we move, so that we do not feel its weight. Just think of the weight of water which lies above a little fish as it swims far down in the sea. Why is it not crushed by it? Just for the same reason; the water is all round the fish, as the air in our ocean is all round us; and it presses so evenly that it cannot be felt in any particular part. Another very wonderful thing about the atmosphere is that what we call the air is made up of two airs, or gases, as different as possible from each other, but mixed so as to make exactly that particular sort of air which is fit for us to breathe.