The marks of the new-birth. A sermon preach'd by the Reverend Mr. George Whitefield, A.B. from Acts XIX. 2. Have ye received the Holy Ghost since ye believed? : Wherein is shewn, I. Who the Holy Ghost here spoken of, is; and how we must all receive him before we can be stiled true believers. II. Scripture marks laid down, whereby we may know, whether we have thus received the Holy Ghost, or not. III. By way of conclusion, an address to several distinct classes of professors, concerning the doctrine that shall have been delivered.