Common and Saving Grace -Edwards

From what has been now observed from the Holy Scriptures of the nature of the Holy Spirit, may be clearly understood why grace in the hearts of the saints is called spiritual, in distinction from other things that are the effects of the Spirit in the hearts of men. For by this it appears that the Divine principle in the saints is of the nature of the Spirit; for as the nature of the Spirit of God is Divine Love, so Divine Love is the nature and essence of that holy principle in the hearts of the saints.

The Spirit of God may operate and produce effects upon the minds of natural men that have no grace, as He does when He assists natural conscience and convictions of sin and danger. The Spirit of God may produce effects upon inanimate things, as of old He moved on the face of the waters. But He communicates holiness in His own proper nature only, in those holy effects in the hearts of the saints. And, therefore, those holy effects only are called spiritual; and the saints only are called spiritual persons in Sacred Scripture.

Men's natural faculties and principles may be assisted by the operation of the Spirit of God on their minds, to enable them to exert those acts which, to a greater or lesser degree, they exert naturally. But the Spirit doesn't at all communicate Himself in it in His own nature, which is Divine Love, any more than when He moved upon the face of the waters.

-Jonathan Edwards-

To fully understand what Edwards is saying here you might need to follow his train of thought up to this comment which is toward the end of his Treatise on Grace. It is well worth the read. Here is a link if you would like to read the entire treatise.

Treatise on Grace By Jonathan Edwards