Good people do good things for other people. By the act of God, Christians are good people because God enables them to do good things and commands them to follow through by pitching in, lending a hand, and joining others who are doing the same, without making a big deal out of it. Do it and forget it, said Jesus; your right hand shouldn't even notice what your left hand is doing.
Christians aren't the only good people; we certainly don't have a patent on it. C.S. Lewis gives thorough attention to this obvious fact in The Abolition of Man. There is nothing especially remarkable about human goodness. It is a common human bond transcending creed, politics, even battle lines. Unfortunately, it is not the only common human bond; there are others less pleasant and more noticeable.
We do good because it is good. Period. It needs no other justification and no ulterior motive. Whether it is expressed by a cup of cold water or by a wild leap in front of a locomotive to push someone else out of danger, it is good in itself.
When it is human goodness, however, it is always temporary; the giver is temporary and so is the receiver. It is of the earth and for the earth. God has made everything beautiful in its time, says Ecclesiastes, but he also has made it unsatisfactory by putting eternity in our minds. None of our achievements lasts forever—yet the Bible implies that something is supposed to.
Eternity is a lot more than unending time; eternity encompasses every dimension in every direction. That is why, to keep our heads straight, we must always separate our modest earthly goals from our eternal hopes. People of faith make the common error of confusing them.
Ecclesiastes advises against that: "That which is, already has been; that which is to be, already has been; and God seeks what has been driven away. Moreover I saw under the sun that in the place of justice, even there was wickedness, and in the place of righteousness, even there was wickedness. I said in my heart, God will judge the righteous and the wicked, for he has appointed a time for every matter, and for every work" (Ecclesiastes 3:15-17). In The Silver Chair Puddleglum puts it more directly to Jill and Eustace—they were told only what to do, not what would happen.
We do temporary good to achieve temporary goals in an uncertain world. God may give them eternal significance, but likely not; we must be satisfied that they were good in themselves, even if temporary.
Out of love and necessity, as a secondary mission, the church does good in the temporary kingdom of the world, but . Its primary mission is to pray and preach the "sacred and imperishable proclamation of eternal salvation," in order to bring everyone willing to come into the eternal kingdom of God. We do not build the kingdom of God by cooking enough meals, lobbying enough legislatures, spending enough grant money, and healing all the sick. All of those together do no more than sustain this dying world on life-support: Do good, die anyway--along with everybody else.
Yet Church history is littered with enterprises and programs that set out on the primary mission and got stuck on a secondary one. We do not know specifically why, but I suspect a general reason because it is a temptation of mine.: It's more attractive to do something and see the visible results than to do what God tells us and then wait upon him for the results.
God gives his kingdom to those who will accept it on faith as his unconditional gift. That's when the eternal glory begins, and believers will see it when they die. As the old gospel song has it:
I have found the joy no tongue can tell,
How its waves of glory roll;
It is like a great o'erflowing well,
Springing up within my soul.
It is joy unspeakable and full of glory,
Full of glory, full of glory;
It is joy unspeakable and full of glory,
Oh, the half has never yet been told.
--Barney E. Warren, 1900
He has made everything beautiful in its time; also he has put eternity into man's mind, yet so that he cannot find out what God has done from the beginning to the end.