Found only six times in the New Testament and limited to books written by Paul (Rom. 6:12; 8:11; 1 Cor. 15:53-54; 2 Cor. 4:11; 5:4), the Greek adjective “thnetos” meant “liable to death” or “mortal.”

Sin is not to reign in our “mortal” bodies (Rom. 6:12).  The “mortal” bodies which die will be brought back to life when the Lord returns (Rom. 8:11), and this will involve a magnificent change (1 Cor. 15:53-54).