Joseph Smith, Jr. Ghost Quotations

For he that diligently seeketh shall find; and the mysteries of God shall be unfolded unto them, by the power of the Holy Ghost, as well in these times as in times of old as in times to come; wherefore, the course of the Lord is one eternal round" - 1 Nephi 10:19

There is a difference between the Holy Ghost and the gift of the Holy Ghost. Cornelius received the Holy Ghost before he was baptized, which was the convincing power of God unto him of the truth of the Gospel, but he could not receive the gift of the Holy Ghost until after he was baptized. Had he not [been baptized], the Holy Ghost which convinced him of the truth of God, would have left him.

No man can receive the Holy Ghost without receiving revelations. The Holy Ghost is a revelator.