I have a god. It might be God, it might not be. If my god is not one who deserves to be my god, then that is idolatry. To be my god is to be that which is my highest end. If something is my god, that means that I desire the good of that thing ahead of the good of any other thing. To have a god is to have one desire according to which all others are ordered.
We all have various desires, aims, goals. These come into conflict with one another. My god is that according to which I decide which desire ranks ahead of which in such a conflict. It is that according to which I can tell whether my desires are good or evil.
I tend to consider myself my god. I order my desires according to how much they serve to please me, how much they make things good for me. To have myself as my god means that I consider how my desires will effect my well-being as the deciding factor in how I order my desires. If I make myself my god, then I will desire what makes life pleasant for me. If I am my god, then I do everything for my own pleasure.
Recognizing that this pleasure need not be merely the pleasures of animals, but might also be those which are unique to humans. Recognize, too, that this manner of life is the one we often suppose others have. If you want to convince someone that something would be good for them to do, you usually try to point out how it will advantage them in some way. The problem comes when you notice that having oneself as one's god backfires: there are great pleasures which cannot be attained if they are done for the pleasure. The attitude of "how can I get the most pleasure out of this social interaction" removes the available pleasure from it. To live with oneself as one's god leaves one unable to do what one considers that one should do.
It is also common to try to make all of humanity one's god. It sounds nice. It is the god of the utilitarian: the ideal of the greatest good for the greatest number. If I have humanity as my god, then my aim is to produce as much pleasure as possible. That would be my aim in life. If humanity were my god, though, it would be bad to mourn if I could help it--unless I thought it would produce more pleasure overall.
It is hard to maximize pleasure in this way. It is also impersonal. I do not matter if my god is humanity in general. If my god is humanity in general, it does not matter what will bring me or those close to me pleasure. If my god is humanity, then it is not any particular humans. Much can be justified by finite and ignorant humans if humanity is their god. Indeed, much looks like something which should be done, if one's god is humanity, which may well turn out poorly.
If God is God, then what I must do is desire his pleasure above all else. My life must become oriented around him. My desires must be evaluated against the standard of whether they are for him or against him. Good desires are those which are for him. It is good to do that which will show one's dependency on him. It is good to act out of one's dependency on him. This is not to desire to fail, but to desire that one's successes would be of God, and one's failures would be such as would allow one to exhibit one's safety in God. One is, then, safe to be weak because it offers a glimpse of the God who is one's strength. It is good to be pained by the evil of the world because in doing so I argue that it is not an evil to be lived with, but to be revolted against. If God is God, then it becomes possible to do what seems foolish because he is the one who brings success.
Would you be free to act without fear of failure? Would you be free to obey in your weakness? Would you be one of those who does what is good? Would you know what is good? Then let all your desires, let all that you do--even what you do against God--be for God. Act for God. When you act against him, let your reaction to that be to let it be made for him. Let your rebellion become his conquest over your sin--as it was on the cross.
Emmanuel: God with us. So that we can act in the knowledge that whatever we do, he is drawing us to himself. He has come as good news--there is no other way to reach the greatest pleasure, whether for ourselves or for any others, apart from seeking him as God.