What is the Gift of the Holy Spirit? – Acts 2:38

               What does the apostle Peter mean when he tells those on the day of Pentecost that had gladly received his word that they would receive the gift of the Holy Spirit?  Were they being told that they were going to have a non-miraculous, literal indwelling of the Holy Spirit?  Is it a reference to the temporary, miraculous spiritual gifts which were received in the 1st century church?  Or was it to be understood as a statement of salvation much like Paul speaking of the gift