Thus the word flesh signifies, and includes all the principles and springs of sin that are found in man, whether they have their immediate and distinct residence in the body or in the soul. The word spirit signifies and includes all the principles of holiness that are wrought in any person, whether immediately residing in soul or body. And among the many places of scripture where they are so used, those words of our Lord himself to Nicodemus, John iii. 6. seem to make this most evident: _What is born of the flesh is flesh, and what is born of the spirit is spirit_; by which he means to assert, that what comes by natural generation tends towards sin, and what is derived from the operation of the Spirit of God leads to holiness. Or, more plainly thus: all the principles of sin spring from mere human nature, as derived from our parents, and are called flesh; and, on the contrary, all the principles of holiness spring from the Spirit of God, and are called spirit; and thence his argument derives the necessity of being _born again_, or born from above. In the first part of these two sentences, flesh and spirit are taken literally for the flesh of man, and the Spirit of God. In the latter end of the sentences, flesh and spirit must be taken figuratively, for the principles of sin, and the principles of holiness. Now since the apostle frequently uses the terms flesh and spirit in the same sense which his Lord and Master put upon them, and talks often on this subject: I shall spend this discourse in shewing the grounds of this figure of speech in my text, and in giving a full explication and improvement of it in the following manner: I. I shall offer some reasons why sin, and the principles of it, are represented by the flesh.—II. I shall likewise propose the reasons why the principles of holiness are expressed by the term spirit. And,—III. Draw some useful remarks from the whole. _First_, Let me shew why sin is represented by flesh, so often in scripture; and I give these reasons for it: