Here is the gist of Galatians Chapter 5. Obviously there were those that were trying to command others to be circumcised, as if though the way to a right relationship with God was to be circumcised. We still have others much like this today telling us that we need to join this group or that, be dunked in this tank or that, say this man-made prayer or another, on and on goes the list. Paul was trying to tell these believers that no such ‘works of the law’ have any ability to save them or keep them. The grounds of salvation is not by any works man can or will do, but is a result of God’s mercy. This was not to say that there was no conditions to salvation, or to say that repentance faith and obedience to the end were not required of man, but rather that they were not the grounds of their salvation,
The law, as a means to forgiveness, was done away with for Christ was the fulfillment of the law in that sense. Just the same, the moral law, was as in as much full force then as it was in the OT. Paul was trying to get the Galatians to understand that NOTHING, including circumcision, could save them or keep them from avoiding the penalty of the moral law, apart from sincere repentance and faith in Christ and in the CONTINUED obedience that is evidenced by a life of ‘walking in the Spirit.’ Paul was teaching these Galatians that the only way they could avoid coming under the condemnation of the moral law, still in full force, was by a life of obedience, again, walking in the Spirit. Circumcision meant nothing if in fact they were a law breaker now. Paul even listed the sins that he felt would bring them back under the condemnation of the law, and even eventually, if they were to remain committing those sins with an unrepentant heart, that they would indeed be severed from Christ. It did not matter what ritual they had previously went through. NOTHING apart from continued obedience to God, via a life of walking in the spirit, would suffice to see them into the kingdom.
Paul was warning these Galatians that they could only be kept in a right relationship with God via walking in the Spirit as opposed to walking according to the flesh. IF they were walking in the Spirit, they would not fulfill the things of the flesh. IF they were fulfilling the things of the flesh they could not entertain a hope of eternal life, for’ those doing those things CANNOT inherit the kingdom’ regardless of the rituals they had went through before. NOTHING will suffice for continued obedience and the fulfilling of the conditions God had mandated to be kept by the power of the Holy Spirit, i.e. to continue to ‘walk in the Spirit’ as evidenced by obedience and abstinence from sin.
Paul was saying that the test whether or not they were walking in the Spirit or walking according to the flesh, and as such under the law and it’s penalties, was by self-examination of their actions. Again, he gave them a list of fleshy sins that were evidence of walking not by the Spirit but rather according to the flesh. He again was warning them that if their lives proved to be walking according to the flesh, as evidenced by the sin in their lives, they had no hope of inheriting the kingdom. Neither circumcision, baptism, or any other outward manifestation of ceremonial law would suffice to avoid the law and its penalty condemning them. The only way to avoid the condemnation of the law, once one had became born again ,was to walk in the Spirit, as evidenced by a life of the avoidance of sin and in clear opposition to walking in the flesh.