Gift of Holy Spirit (Acts 2:38,39)
    Can we determine exactly what was the "gift of the Holy
    Spirit" outside of the context of these verses (Act 2:38,39)? Or should we read
    the whole context for the best picture? Undoubtedly the latter.
    
    Firstly, the main "gift" that anybody received that day was
    the gift of forgiveness of sins: hearing all that Peter and the apostles
    preached to them, the men of Israel were "cut to the heart" (v 37) -- they knew
    they were sinners, murderers even! And their only hope was to repent and be
    baptized; then their sins would be forgiven!
    
    In the context, this was an absolutely extraordinary thing --
    in fact, it was the most extraordinary thing imaginable! Here was a man offering
    them the means by which all their sins could be forgiven: something which the
    Law of Moses could not really do, could never do -- because the continual
    offering of sacrifices only served as a reminder of past sins, and had to be
    repeated time and again, and never quite accomplished the trick!
    
    We may tend to downplay this aspect, not because we don't know
    it is the most important, but because we almost take it for granted: that's what
    God does, through Christ -- He forgives our sins. It needs to be stressed as
    much as we possible can: THROUGH CHRIST, GOD FORGIVES OUR SINS! This IS the
    doctrine of grace.
    
    Compare the incident in Mar 2, where Jesus tells the lame man,
    'Your sins are forgiven'. Those who are watching are shocked: 'Who can forgive
    sins but God alone?' To which Jesus replies: "Why are you thinking these things?
    Which is easier: to say to the paralytic, 'Your sins are forgiven,' or to say,
    'Get up, take your mat and walk'? But that you may know that the Son of Man has
    authority on earth to forgive sins... (He said to the paralytic), I tell you,
    get up, take your mat and go home' " (Mar 2:8-11).
    
    The point is: anybody can SAY, 'Your sins are forgiven', and
    who's to know if those words have any power? In other words, there is no visible
    sign to prove that one's sins have been forgiven. But not anybody can SAY, 'Get
    up and walk!' and see it happen. 
    
    So the miracle of healing was the visible sign of the power of
    God, in Christ, to forgive sins. The visible miracle confirms Christ's power to
    perform the invisible miracle!
    
    Something similar is happening in Acts 2: the forgiveness of
    sins was THE great gift of God -- always has been, always will be... BUT it was
    (and is) very useful for men and women to SEE some visible sign of God's
    presence and power so as to truly believe that their sins have been
    forgiven.
    
    Now it would be simple for us if, in Act 2:38, the "gift" of
    the Holy Spirit meant (a) the gift brought by the Holy Spirit, which is
    forgiveness of sins, instead of (b) the gift of God, which is the Holy Spirit.
    But, according to the textual authorities, it doesn't -- it means plainly (b)
    and not (a). What the authorities call a "genitive of apposition"; the gift
    consists of the Holy Spirit. 
    
    So in Act 2:38,39 there are two things happening, not just
    one: there is forgiveness of sins (plainly the most important), AND there is the
    Holy Spirit being given.
    
    But to whom? and how? It is useful to note, in the last part
    of Acts 2, the description of the new life of the baptized believers: 
    
    
        "They devoted themselves to the apostles' teaching and to the fellowship, to the
        breaking of bread and to prayer. Everyone was filled with awe, and many wonders
        and miraculous signs were done by the apostles. All the believers were together
        and had everything in common. Selling their possessions and goods, they gave to
        anyone as he had need. Every day they continued to meet together in the temple
        courts. They broke bread in their homes and ate together with glad and sincere
        hearts, praising God and enjoying the favor of all the people. And the Lord
        added to their number daily those who were being saved" (Act
        2:42-47).
    Notice all the things they did, and all they were blessed
    with... but -- look! -- the wonders and signs were all done by the apostles...
    not by all the other believers. It looks like some might complain, 'They (the
    apostles) got all the good stuff!' But who's complaining; forgiveness of sins
    was the desideratum (JT word: the thing greatly to be desired) -- and they ALL
    had that! Everything else (even wonder-working power) was secondary.
    
    So how did they all receive the gift of the Holy Spirit? Was
    it simply in seeing and witnessing that God's Holy Spirit power was truly and
    actively working in their midst, to confirm the power of God to forgive their
    sins? I think that about covers it!
    
    And would their generation and future generations receive the
    same promise? Surely. The forgiveness of sins. A forgiveness of sins attested by
    Holy Spirit signs and wonders (at least for the second -- and possibly third --
    generation), and a forgiveness of sins (attested by church history and the
    written word and fulfilled prophecy, etc) for all succeeding generations, up to
    and including ours.
    
    And... don't forget... God's Holy Spirit power would still be
    at work, in less visible and less obviously miraculous ways, in each successive
    age... BUT the real gift was the forgiveness of sins.