1. Why is this passage listed among difficult passages?
The difficulty in this passage is this. Exactly what power is Jesus conferring to his disciples?
We are very influenced by the discussion in Mark 2:1-12. There the teachers of the law repeat the accepted wisdom that God alone can forgive sins. Jesus’ words and actions show that he also has power and authority on earth to forgive sins. In what sense is he now in the passage in John delegating this authority to us and to whom specifically is he delegating it?
2. How do we deal with the difficulties in this passage?
There is not an exactly similar passage to help us. The closest is Matt. 16:19 where Jesus speaks to Peter about binding and loosing. This similarity has raised the additional question as to whether the authority of forgiveness was also being given to Peter. But that seems an unnecessary complication as the Matthew saying does not occur in the same upper room post-resurrection context at all and does not involve forgiveness.
According to commentator Merrill Tenney, both passages contain future perfect tenses which indicate completed action viewed from a point in the future. Tenney’s conclusion from this fact is, “The delegation of power to the disciples to forgive or retain the guilt of sin thus depends on the previous forgiveness by God.” (p. 194 Expositor’s). In other words, we need to always remember that “forgiveness of sins will be preached in his (Jesus’) name (Lu. 24:47).” We can never forgive sins on our own. But, for example, a pastor can, on the authority of this command, pronounce a person forgiven who has met Scriptural conditions of confession, trust in Christ’s work and repentance, which is turning away from evil. The pastor might do so by quoting a verse of assurance to the person such as 1 John 1:9 or Isa. 1:18. Assurances of forgiveness by the writers of the NT are like this. For example Rom. 4:7 or Eph. 1:7, Acts 2:38.
3. What are the key truths or inspirational messages of this passage?
The key to the passage is verse 21, “As the Father has sent me, I am sending you.” This tells us that the big idea in this passage is the transfer of the parts of Jesus’ mission that are not unique to his disciples. Without verse 23, we would definitely have reserved forgiveness of sins for Jesus uniquely. But, Jesus told his disciples in Matt. 28:18 that he had all authority. Flowing out of that authority, he assigned them the great commission. This passage in John functions in John as the great commission to the disciples. It also is accompanied with words of empowerment about receiving the Holy Spirit and having authority to pronounce forgiveness. Jesus has not given us the task of being sent to help others understand and receive his forgiveness, without sending us his Spirit and sharing his authority too.