Romans 8:7 does not prove Total Inability because we have numerous scriptures showing that the natural man can and does obey God at times.
Again, Cornelius was neither saved, nor did he have the Holy Spirit, and so according to Romans 8:9 did not belong to Christ at this point.
Rom 8:9 But ye are not in the flesh, but in the Spirit, if so be that the Spirit of God dwell in you. Now if any man have not the Spirit of Christ, he is none of his.
Nevertheless, Cornelius clearly believed in and feared God, he was devout, he prayed always, and he gave much alms and did "righteous works" according to the Word of God.
Therefore Rom 8:7 cannot prove that unregenerate man is unable to listen to and obey God.
Jesus showed the same in the garden, none of his disciples had the indwelling Spirit, as the Spirit was not yet given (Jhn 7:39) but Jesus himself said their natural spirit was willing to be obedient, but their flesh was weak.
Mat 26:41 Watch and pray, that ye enter not into temptation: the spirit indeed is willing, but the flesh is weak.
This verse completely refutes the doctrine of Total Inability.
Another example that refutes Total Inability is the Philipian jailer. He could not possibly have been regenerated when he burst in asking how to be saved, because he had not yet believed. And until you believe you are dead in sin.
Acts 16:29 Then he called for a light, and sprang in, and came trembling, and fell down before Paul and Silas,
30 And brought them out, and said, Sirs, what must I do to be saved?
31 And they said, Believe on the Lord Jesus Christ, and thou shalt be saved, and thy house.
32 And they spake unto him the word of the Lord, and to all that were in his house.
33 And he took them the same hour of the night, and washed their stripes; and was baptized, he and all his, straightway.
The Philipian jailer was not saved, because he had not believed yet, and yet he had a real and sincere desire to be saved.
Calvinists can say what they will, there is MUCH scripture that easily refutes Total Inability that they must explain away.
People should listen to the scriptures and not the false doctrines of men who must wrest scripture to make their doctrine work.