There are few more guaranteed causes of bitterness than feeling let down. The church in Corinth felt let down by Paul because they didn't understand the reasons why he said he would pay them another visit and then failed to do so.

When bitterness abounds it is extremely easy to mistake and misrepresent (either deliberately or unintentionally) the motivation of the person you feel bitter towards. So it was in 2 Corinthians. Rather than assume that there might be good reasons, they automatically knee-jerked to admonition and accusation. And the accusations are bitter indeed:

You behaved duplicitously and insincerely (1:12)

You behaved just like the world (ie, saying you would come but dropping out when you got a better offer) (1:12)

You didn't mean what you said. You were deceitful, saying "yes" when you really meant "no" (1:17)
You have set about deliberately grieving us (2:4)

Basically "we don't trust you anymore." Now that is painful when levelled at anyone, but when levelled at a gospel minister (and even more an apostle) it is potentially devastating. If it is either true, or false but goes unrefuted, it is likely to be game over for Paul's gospel ministry which depends utterly on credibility and integrity. I know Christian leaders who have had their integrity wrongfully questioned and have chosen to not refute allegations, on the grounds that they don't want to escalate tensions. That is not the line Paul takes here.

It is critical to note the tone of his refutation. He doesn't just issue a rebuttal. Rebuttals alone might win arguments but they don't win back friends. Instead Paul both refutes and appeals: "I want you to share my joy. I want you to know the depth of my love for you. I will boast in you in the day of the Lord Jesus."

The Corinthians got one thing right. Paul had agreed to visit and had changed his mind. What they didn't know - and couldn't easily check in an age before mass-communications - was why. Sadly they assumed, seemingly automatically, the worst interpretation of events, namely that he was unreliable, worldly and didn't care about them.

The actual reason he changed his mind is that since making the plans he had made an unscheduled stop in Corinth that had resulted in pain for both him and them (2:1). It seems that after much thought he wrote instead of returning in person (2:3-4).

So here is a situation of relational breakdown. The two key factors are (a) that they misread and mistrust his motives and (b) he writes an appeal based on love, rather than reacting in kind. Interestingly there is the danger of a ministry being damaged here over something as trivial as a travel itinerary. There is nothing doctrinal at stake in the fall out.

But there is in the way Paul responds. He explains and appeals to them that he has behaved with sincerity towards them, but backs it up with why gospel ministers must always behave like this: we are "yes" and "no" because God isn't (v18-22). God is utterly sincere because he is utterly steadfast. All his promises have always been "yes". He doesn't change his mind or go back on things he said. Our behaviour is to agree with this wholeheartedly and unambiguously - we give it a loud "Amen" by how we base our behaviour on God's (1:20). That is just how God-anointed, Christ-bought, Holy Spirit-filled people live (1:22).

I have seen, and been in, situations where I believe that other Christians have behaved extremely badly. I can think of some instances where people have assumed that I have too. I know of a couple of situations at the moment in which the most emotionally tempting route for the aggrieved party is to justify themselves by un-Christianing the other lot in their minds because of the pain they feel ("if they were really believers they wouldn't treat me like that").

Let's learn the three lessons from 2 Corinthians 1:

you can't always tell motives

It is OK and often necessary to refute false allegations

The final outcome we want is not to be seen to be in the right, it is restored relationships. Therefore appealing in love is a much better response than mere rebuttal