No you are again trying to come to a conclusion by assuming. The passage is true and it agrees with they rest of the bible. No Christian can be carnal in their walk as that means they are practicing sin which is impossible for the believer. The problem is not that believers are carnal but that many who claim to be believers are not believers.
You are right it agrees with Paul who said to the Corinthians ye are Carnal. It agrees with Peter who said Lot was just but vexed his soul daily and it agrees with John who says 1 John 2:9 He that saith he is in the light, and hateth his brother, is in darkness even until now.
10 He that loveth his brother abideth in the light, and there is none occasion of stumbling in him.
Those that say they are in fellowship and hateth His brother are in sin, and He that continues "meno" (abideth) in the light there is no occasion to stumble. Very clearly abiding or continue has to do with the believers walk and not the believers salvation.
I see you still se abideth to mean salvation but the Greek meno doesn't reinforce that belief.
Here is Strongs on Meno:
to remain, abide
in reference to place
to sojourn, tarry
not to depart
1a to continue to be present
1a to be held, kept, continually
in reference to time
to continue to be, not to perish, to last, endure
1b of persons, to survive, live
in reference to state or condition
to remain as one, not to become another or different
to wait for, await one
Notice especially this "in reference to state or condition" to be a state or condition of walking with Christ. If we walk with Christ we sin not.
Notice 1 John 2: 28 And now, little children, abide in him; that, when he shall appear, we may have confidence, and not be ashamed before him at his coming.
A command to abide in Him, again the word Meno to continue, sounds like John is saying we must make it a practice to continue with Christ yet more support that a believer can walk in Christ or walk the opposite.
Jesus even taught that we must meno in Him, John 15:4 Abide in me, and I in you. As the branch cannot bear fruit of itself, except it abide in the vine; no more can ye, except ye abide in me.
We cannot produce fruit if we are not continuing in fellowship and service to the Vine our Lord Jesus Christ. Paul uses it in 1 Corinthians 3:14 If any man's work abide which he hath built thereupon, he shall receive a reward.
15 If any man's work shall be burned, he shall suffer loss: but he himself shall be saved; yet so as by fire.
If our work abides (survives) he shall have his eteranl reward but if it shall be burned the believer suffers loss yet so he himself shall be saved. Again the carnal believer is building wood, hay and stubble and therefore will see his works be burned up but he will still be saved.
Scripture is very clear and 1 John 3:6 says If and maybe we will abide in Christ then we will not continue in sin, but if we fail to abide in him we continue in sin.