The passage below (which you quoted) is concerning contributing (sowing) to him who is instructing.
Gal 6:6-10 Now let him who is being instructed in the word be contributing to him who is instructing, in all good things." (7) Be not decived, God is not to be sneered at, for whatsoever a man may be sowing, this shall he be reaping also, (8) for he who is sowing for his own flesh, from the flesh shall be reaping corruption, yet he who is sowing for the spirit, from the spirit shall be reaping life eonian." (9) Now we may not be despondent in ideal doing, for in due season
we shall be reaping, if we do not faint." (10) Consequently, then, as we have occasion, we are working for the good of all, yet specially for the family of faith."
The reaping "in due season" is in this life. Fainting has nothing to do with "he who endures to the end, the same shall be saved." This has nothing to do with salvation or loss thereof but of reaping the benefits in this life of (figuratively) sowing in this life, or being corrupted by false teaching.
Also, friend, in the phrase: "if we do not faint" the words "if we do" are not in the Greek and are just supplied for an idiomatic translation. It might be good to read it thusly: "Now we may not be despondent in ideal doing, for in due season we shall be reaping, [while] not faint[ing]," Also, the word "no
t" (there the "t" is in lightface in the CLNT) is not the absolute "not" but the conditional, relative.
Now then if we recast the declaration in the indicative we get this: "Now we shall
not be despondent in ideal doing, for in due season we shall be reaping, [while] not faint[ing]." So you see, Bob, the Galatian passage is not in any way equivalent to "Therefore if your eye offends you, pluck it out
" which you posted.
Eonian life is a gratuitous gift. It was not earned and cannot be lost for those of us under grace and not under law. So how is one "reaping life eonian"? The word "reaping" has to do with fruit. Paul is not saying that if you don't give to him who is instructing you that you will miss out on life eonian. That is just not possible. But it is possible to miss out on reaping the benefits of life eonian in this present life as we travel through this life.
Also "reaping corruption" has to do with the Galatians sowing to the flesh (which is what the book is about) rather than spirit. They begain in spirit and were trying to complete themselves in flesh, hence were sowing to the flesh and were being corrupted. They were being corrupted by the bad influence of the circumcisers and were cutting off (no pun intended) their support for the teachers of grace. So Paul asked the Galatians: Where is your happiness? (Gal.4:15). They were not reaping the fruit of happiness.
"The literal, future allotment of eonian life is our expectation in grace (cp Titus 3:7; Eph.2:5-7), and will be granted even where there is persistence in sin (cf Rom.5:20-6:1). Therefore, the "reaping" of "life eonian," here in Galatians 6:8, which speaks of an attainment as the result of works, must be identified not with future, life eonian itself, but, through the figure of metonymy, with that which is associated with it even now. It is one's faithful relationship to the only true God, as well as with His Son, our Lord Jesus Christ: "Now it is eonian life that they may know Thee, the only true God, and Him Whom Thou dost commission, Jesus Christ" (John 17:3). In this same sense, Paul sought to be attaining to the resurrection that is out from among the dead" (Phil.3:11), entreating Timothy similarly to "get hold of eonian life" (1 Tim.6:12). " (James Coram, Unsearchable Riches
, vol.88, p.209).
BTW how does a person determine whether he is under the gospel of the circumcision or uncircumcision?
If you circumcise to maintain righteousness and the law, that would put you in the circumcision camp. However, under today's administration of grace with Israel set aside, it is impossible (I think) to be in the circumcision camp, though to be sure, one can enter into the error the Galatians did and think one needs circumcision to perfect oneself in the flesh.
Being under the evangel of the Uncircumcision means one is not under the law or under law mixed with grace. Therefore one is under the evangel brought by Paul to the nations (that's us).
Here is a handy dandy chart by Jeff Priddy:http://www.weltmanager.de/worldmanager/TheTwoEvangels.html