Wow! So you believe that almost no modern Christian is saved. The whole of the Baptist denomination is accursed as well as pretty much every other sect of Christianity that exists.
Paul, in Galatians, is not talking about their salvation but of their walk...
Galatians 3:3 Are you so foolish? Having begun in the Spirit, are you now being made perfect by the flesh?
He tells the Colossians something similar...
Colossians 2:6 As you therefore have received Christ Jesus the Lord, so walk in Him,
When Paul says in Galatians chapter five....
Galatians 5:2 Indeed I, Paul, say to you that if you become circumcised, Christ will profit you nothing.
...he isn't trying to tell them that they're going to Hell. He's saying that Christ will profit them nothing in regards to their daily lives, in their effort to live a righteous life that bears fruit unto God because they are trusting in their flesh which can produce no such fruit. The only thing that has the power to perfect them is the same thing that saved them in the first place which is faith in Christ.
If this were not the case, then grace would be turned into law but with a different set of commandments. Thou shalt not be circumcised, thou shalt not be baptized, thou shalt not tithe, thou shalt not...fill in the blank. If you do any of these things, you're not in the faith and bound for Hell fire. That's not how grace works! The law had a lot of both "thou shalt not do this or that" as well as a lot of "thou shall do this or that". Grace did not turn all of the "thou shall do this or that" commands into "thou shalt not do this or that" commands. Grace isn't about commands, its about freedom. The motive behind grace is love, not fear.
Salvation by grace is about God having subjected His Son to the penalty for our sin. And not just some of our sin but the whole of it, including the sin of getting circumcised or water baptized, thinking that you're obeying God. Such works will be tested by God on judgment day. Those works which were born of faith and love will receive reward, those that were born of the flesh will be burned up and...
1 Corinthians 3:15 If anyone’s work is burned, he will suffer loss; but he himself will be saved, yet so as through fire.
Clete