6 One who is taught the word must share all good things with the one who teaches. 7 Do not be deceived: God is not mocked, for whatever one sows, that will he also reap. 8 For the one who sows to his own flesh will from the flesh reap corruption, but the one who sows to the Spirit will from the Spirit reap eternal life. 9 And let us not grow weary of doing good, for in due season we will reap, if we do not give up. 10 So then, as we have opportunity, let us do good to everyone, and especially to those who are of the household of faith.
The fact is - and this is the general principle enunciated here - all life is lived under the shadow of judgment. It is an inexorable, inescapable fact of our existence, operating all the time, not merely at the end of life, and Paul has in mind the harvest that is reaped in this life as much as in that which is hereafter. He was already seeing some evidences of a sorry harvest in the Galatian Church. That is what disturbed him so much, and made him write as warningly as he did. Nor would he have had far to look, in Scripture, for illustration of his point. The story of Abraham and Lot in the book of Genesis is a practical example of the two alternatives before us of sowing to the flesh or sowing to the Spirit. Lot's history is significant and characteristic, showing a downward progression, from 'looking on the cities of the plain', through 'pitching his tent toward Sodom', to 'sitting in the gate of Sodom'. There is nothing stationary or static in the life of the flesh, there is a momentum involved in it, and the harvest is always sure and inevitable: his testimony was scorned and ignored by the citizens of Sodom. But how could he have expected to reap a spiritual harvest, when he sowed such seed? In contrast, Abraham's sowing was to the Spirit, and he set his mind on things that were above. And the reaping? He became the friend of God, and the father of the faithful! God is no man's debtor!