This is just a weird idea -- rejoice in suffering? Really, Pete? You having a flashback to the time when you were in the running for Most Clueless Disciple? What the heck?
OK, maybe I'm a little too quick here. Lots of times we read things in the Bible and on first glance, they seem to make no sense, kind of like this idea of rejoicing in our suffering. Let's worry at it a little bit and see if we can tease out something that we can understand.
First off, we can eliminate the idea that some people seem to have about boasting of their suffering. You know what I mean: The person who, when you tell them you've had a tough day, can't wait to tell you how much tougher of a day that they've had. Or the person who dramatizes every little scrap of adversity into Shakespearean dimensions. Lots of times that person can be a boss at a job -- "Sorry Mr. Snidely, I was late because of traffic." "Well, I had to have my leg amputated and reattached during rush hour and I made it on time!" That sort of thing. Peter doesn't seem to be talking about that at all.
And he talks about a very specific kind of suffering; the kind when you suffer unjustly for doing the right thing. Not just plain old everyday suffering, like someone who isn't happy because a meteor didn't hit their house. Again, there's no call for rejoicing when things go wrong just because they go wrong. Only the kind of suffering that happens when you do the right thing but are punished because of it.
Because, as Peter points out, there's no credit for taking your deserved punishment. "This con man swindled old people out of their retirement money and was sentenced to 20 years in prison, and he served every day of it! Let's give him a round of applause!" Things like that don't happen for adults, because we expect adults to accept the consequences of their actions. We may applaud children for, say, not complaining when they get sent to their rooms for transgressing some rule, but that's because we're trying to teach them that actions have consequences and we are pleased when they learn that lesson.
So we've sliced away a bunch of things this idea of Peter's doesn't mean, and...I'm still lost. Rejoice when you suffer unjustly for doing right? That runs counter to everything we understand about how we're supposed to act in society, doesn't it? Famous people, personal heroes, political philosophy and what have you, none of it matches this idea of rejoicing in suffering unjustly for doing right! If our rights are trampled on, we're told to stand up for them! If we are unjustly accused, we're called to speak out against it.
I've never heard anyone say we should be glad when people accuse and persecute us for doing the right thing. It's just weird.
BUT, Christians, we've heard one person say that, haven't we? We've heard one person respond to unjust punishment with love and forgiveness, to say of the very men who were killing him, "Forgive them, Father, for they know not what they do." And in fact, Peter calls Christ our example and says that we should do what he did in this regard. Which is, as I noted, very very hard because of how contrary this instruction runs to our society's teaching. If we do follow it, though, Peter says we find ourselves rewarded for doing as Christ did for us.
I don't do well with this, and I doubt I ever will. But I'll keep working towards it and taking steps. Something kind of similar may help serve as an example. Like most folks, if I'm discussing something with someone and we disagree, I hold my ideas out because I think they're right. They're not right because they're my ideas, but if I've done my homework and researched them properly, I can be pretty sure they're right and so that's why I hold them. Of course, that doesn't always convince people, does it? Not the people I've argued with, anyway.
What I've tried to make myself do more and more often is stop instead of trying to win the argument, even when I can. I can put together the facts and line up my data and show the other person just where they're so far off-base and I will have won the argument. But I've tried to not do that. Because sometimes, of course, I haven't won and I've overlooked something, but also because sometimes winning an argument means losing a relationship.
And a couple of times since I've been trying to do this, someone has come up to me later on and brought up whatever it was we disagreed about, and said, "You know, I looked into what we were talking about the other day and it turns out you were right." But that's not the win, the win comes in that whatever friendship I had with that person before is maintained or strengthened because I didn't slam the ball home over their heads and make a dunkface on them when doing it. I've even been able to offer the same kind of words to someone who's been "righter" than me and found out it works the same the other way.
Which is a pretty good reward, and a pretty good model of how I might even share the faith with someone who wants to know more about it, and maybe a hint of why Peter might suggest to us to rejoice when we suffer unjustly for doing right, as hard as it may be now and may stay in the future to do that.