Again, not only an arbitrary assumption, but one standing in contradiction to the revelation of the Spirit, for the carnal mind is at enmity with God, for it is not subject to the law of God, neither indeed can be.
No ability to obey the commandment. That's what Paul said, and Jesus and I agree.
Again, you are assuming that Total Inability is true, and that this verse is teaching Total Inability, when that is not necessarily the case. In fact, Romans 8:9 actually refutes your view, as it says that until a man has the indwelling Holy Spirit he is still in the flesh. But MANY scriptures show a person does not receive the indwelling Spirit until AFTER they believe.
Gal 3:2 This only would I learn of you,
Received ye the Spirit by the works of the law,
or by the hearing of faith?
Paul's question to the Galatians demands the answer that they received the indwelling Spirit AFTER first hearing and believing the gospel.
Jhn 7:38He that believeth on me, as the scripture hath said, out of his belly shall flow rivers of living water.
39 (But this spake he of the Spirit,
which they that believe on him should receive: for the Holy Ghost was not yet given; because that Jesus was not yet glorified.)
All of the disciples (except Judas) and many thousands of Jews (and some Gentiles) believed on Jesus before the Holy Spirit was given. The disciples did not receive the Holy Spirit until after Jesus rose from the dead.
If you isolate Romans 8:7 from all other scripture it indeed does SEEM to argue that a person cannot possibly believe while they have a carnal mind. But when viewed in light of much other scripture directly dealing with the same subject it is easily shown this interpretation is false.
There is much other scripture that shows a person can believe before they receive the Spirit and are still "in the flesh";
Acts 2:38 Then Peter said unto them, Repent, and be baptized every one of you in the name of Jesus Christ for the remission of sins,
and ye shall receive the gift of the Holy Ghost.
Peter told these Jews to repent and believe on Jesus for the remission or forgiveness of their sins and to be baptized, and THEN they would receive the Holy Spirit.
Eph 1:13 In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also
after that ye believed, ye were sealed with that holy Spirit of promise,
This verse is very plain and clearly shows a person receives the Spirit after first hearing and believing the gospel.
I could show many more, but all of these verses show your interpretation of Romans 8:7 error. The natural man can believe, and if he does he receives the Spirit. You cannot pull one verse out of context to refute many other scriptures that directly deal with the same subject.