The day of Pentecost was 50 days after Resurrection Sunday so how does John manage to speak of the coming of the Spirit in his gospel account (20: 19-23)? Are these two accounts to be harmonised somehow are just recognised as contradictory?
I wouldn't accept either of these approaches. Both are concerned to bring everything in the Scriptures under the rubric of historicity when the Scriptures evidence in many instances a lack of concern for historical exactitude. The Scriptures were not primarily given to tell us about history. They are intended to "open the mind to the salvation which comes through believing in Christ Jesus" (2 Tim 3:15, Phillips). To understand both St John and St Luke's differing accounts, we would have to examine their different renditions of the coming of the Spirit in the context of their gospel accounts.
Despite the differences in timing, both connect the coming of the Spirit with the mission of the church. According to one writer, John's language is heavily freighted with the middle-eastern patronage system in mind: patron, brokers, and clients. (God the Father is the patron, who has all the goods necessary for life; Jesus is the broker, who dispenses those goods; and humanity is the client, who receives those goods and returns loyalty to the patron through the broker.)
Additionally, St John mentions many times that Jesus is sent by the Father; now, he sends the disciples as he has been sent. And breathes -- only used here in the NT -- on them, connecting their mission with the forgiving and retaining of sins. This passage tends to be avoided by Protestants because it raises embarrassing questions about its meaning. Is this a power that the Church has or individual Christians, or the institutional church?
This gospel does not major on the forgiveness of sins as such, which is not specifically mentioned in John except here (although,the idea of forgiveness is implied when Jesus was first revealed in chapter 1 as "the Lamb of God").
Like many others, I know, I have struggled over the issue of forgiveness: some Christians believe that we should forgive anyone who sins against us regardless of any show of repentance. These Christians interpret all the forgiveness passages of Scripture consistently with that view. However, I stand with those who say that forgiveness is ideally a relational process between people leading to reconciliation. In scripture, forgiveness between Christians is usually on the basis of repentance or being asked for it (see Luke 17:3-4). Even the well-know sections in Matthew (18:15-35), both presuppose repentance or lack thereof.
I do also accept that Jesus forgave his tormentors from the cross because of their ignorance and blindness and that that provides us with a model for forgiveness of a certain offence in certain situations. Nevertheless, Christians are not to harbour retaliatory thoughts towards those who have wronged them because the Lord is the Judge of us all (Rom 12:19).
