Joseph F. Smith on "the Spirit of the Lord" and "the Holy Ghost"

The question is often asked, is there any difference between the Spirit of the Lord and the Holy Ghost? The terms are frequently used synonymously. We often say the Spirit of God when we mean the Holy Ghost; we likewise say the Holy Ghost when we mean the Spirit of God. The Holy Ghost is a personage in the Godhead, and is not that which lighteth every man that comes into the world. It is the Spirit of God which proceeds through Christ to the world, that enlightens every man that comes into the world, and that strives with the children of men, and will continue to strive with them, until it brings them to a knowledge of the truth and the possession of the greater light and testimony of the Holy Ghost. If, however, he receives that greater light, and then sin against it, the Spirit of God will cease to strive with him, and the Holy Ghost will wholly depart from him. Then will he persecute the truth; then will he seek the blood of the innocent; then will he not scruple at the commission of any crime; except so far as he may fear the penalties of the law, in consequence of the crime upon himself. (Pres. Joseph F. Smith, “The Holy Ghost and the Holy Spirit,” Improvement Era volume XI no. 5 [March 1908]:381-82)