When Paul came to Ephesus, so we are told in the Acts of the Apostles (ch. 19), he asked the small band of disciples he found there, “Did you receive the Holy Spirit when you believed?” To which they replied, “No, we have never even heard that there is a Holy Spirit” (v. 2). Paul then instructed them on baptism “in the name of the Lord Jesus,” with which was involved the reception of the Holy Spirit (v. 5), and proceeded to baptize them and lay his hands on them, after which, we are told, “the Holy Spirit came on them, and they spoke with tongues and prophesied” (v. 6). Paul’s instruction on the Holy Spirit on that occasion would have consisted of the bare essentials, presented as briefly and simply as possible. Even so, it must have dealt with such questions as, is it really the Holy Spirit who acts in our lives? who is this Holy Spirit? and what does the Holy Spirit do?