God created our world, and in this world He created an angel and a human. How are they different from other creatures? In that God gave both the angel and the human reason and freedom, so that before them opened the possibility either to rise to the heights of love, or to fall into the abyss of self-love; to walk the path of holiness, or the path of sin. Where does the path of sin begin? If we trace it to its very source, we will see that sin begins when an angel or a human loves himself more than God. Likewise, holiness begins when an angel or a human loves God more than himself. The sinner sacrifices others for his own sake, while the saint sacrifices himself for the sake of others. It is impossible to kill a person unless you first place your own interests above his, and it is impossible to give another your last piece of bread unless you place his interests above your own. Thus, in every feat of virtue this sacrifice is seen, just as in every crime an anti-sacrifice is seen – the preference of one's own interests and desires over the interests and desires of other people and of God.
Why did God grant freedom to angels and humans? So that angels and humans could love. Without freedom there is no love; it is impossible. That is why it is said: you cannot force someone to love you. What can you do if you love, but are not loved in return? It is impossible to force love. Thus, God gave angels and humans freedom so that they might love Him, and having loved Him, be united with Him and become like Him.
Such is the Creator's design for us – that each of us should become holy by loving Him. But not all of us choose this. And this happened right from the beginning, when one angel – Satan – fell into the cesspool of self-love, followed by some other angels. They were all created good, but they chose evil. Then, at Satan's instigation, the first people – Adam and Eve, our forefathers – also fell away from God.
Sin is like a swampy bog, and the one who falls into it cannot get out on his own. A person stuck in a swamp cannot pull himself out. He needs either something to grab hold of to climb out, or someone who will come to him, take him by the hand, and pull him out. Without this – no matter what the person tries to do, the swamp will only suck him in deeper.
And so the Lord decided to come and pull us out of this deadly swamp of sin. God Himself came and saved us by His sacrifice on the cross.