The Spice Girls and Westlife can do it – sort of. Why can't Christians deal with comebacks?

Devoted fans all over the world this week found out that the rumours were true, the whispers weren't wicked and their dreams were becoming reality as The Spice Girls announced a comeback tour...well, almost.

Baby, Ginger, Scary and Sporty have come back together to spice up their bank balances, but sadly it will not be a full reunion as Posh has decided this time around it's not for her. Musically the loss is huge. Some raised the first alarms: 'I don't get it, who's going to sing Victoria's bits?' asked comedian David Morgan on Twitter, echoing the concerns of music-lovers worldwide.

ReutersThe Spice Girls (L-R) – Geri Halliwell, Melanie Chisholm, Emma Bunton, Melanie Brown and Victoria Beckham – announced a reunion tour, but Posh won't be taking part.

Theories persist of a long-standing feud within the group (not helped by Mel B's choice of Halloween outfit) but when asked about performing without Posh, Mel C said: 'It is tough because obviously she's a huge part of the band – she still is... we really support each other and the decisions we make. She's really supporting us. That's a big part of our ethos... She's very excited for us.' Following the announcement, Victoria herself confirmed she would not be joining, but wished the others 'love and fun'.

It's not the first incomplete comeback this year. Just a few weeks ago, Westlife announced a reunion tour without Brian McFadden. 'I don't think we feel that anybody is missing here today – and that is not in any bad way, that is just what Westlife is to us,' said Mark Feehily from the band. Two years ago, while appearing on a chat show, Kian Egan said: 'Brian McFadden left the band after four years, so if we were reforming, we won't be reforming with Brian McFadden.' Back in April McFadden himself tweeted that a major offer was on the table for a five-piece Westlife reunion but that 'ego' was stopping it going ahead. He later deleted the tweets.

I guess there's a pretty obvious difference in the two tales. One a band who are having to say goodbye to a member who is choosing not to join in. Another a band not willing to let a member back after they chose to walk away.

A number of years ago I was at a conference with a colleague. We were both speaking and taking part in workshops at the event and during a break we had a chance to go and meet a friend of his for some lunch. The conversation turned to why this particular person wasn't attending the conference and it turned out that he, along with several others, had decided not to go because one of the key speakers was a former clergyman of the denomination who had resigned several years ago and gone to work for another church movement. They articulated that they couldn't understand why they'd invited this person to be a keynote speaker. They were, after all, a dissenter.

That word didn't sting me at the time. If I'm brutally honest, I think part of me, in my youthful zeal, possibly agreed. Why should someone who has 'walked away', 'given up', 'joined the other team' be allowed to come back and speak to those of us who have 'lasted the course', 'stuck it out' or 'stayed loyal'? Why should a microphone be given to someone who chose to leave, when others have stayed 'true' and don't get the chance to be heard? Besides, we're doing just fine without them. Life went on, good things happened after they left so we probably didn't need them in the first place.

It didn't sting me at the time, but it does now. I wonder how often I wrote off wisdom because I wasn't willing to let go of someone making a different choice? I wonder how often I circumnavigated a challenge because I couldn't see past someone's 'member' status? I wonder how often I dodged a dissenter when what they were actually pointing towards was divine?

Maybe some doors are too heavy to hold open? Maybe some burnt bridges can't be rebuilt?

Don't get me wrong, sometimes the departure is too divisive and the exit too extreme. Some people seem to want to slam the door, burn the bridge and fling a grenade over their shoulder on the way out. It can take a long time to repair that damage and often there can be a fear of wiring up another microphone when the last thing you heard was so hurtful or hateful.

Sometimes the departure is for the best. You find new harmonies, you realise the person wasn't a right fit for you and you for them. Their absence leaves less of a hole and more of a space that can be filled with joy and a peace no one realised was missing and needed. It can be the right thing.

But I wonder if too often we rush to make that the case when, in fact, all it would take to repair and restore might be as simple as an invitation. Another seat at the table, another stool on the stage, another voice in the song. Because while it seems unlikely that Brian McFadden will be making any guest appearances with his former bandmates, hope still holds on for a Posh surprise at one of The Spice Girls' gigs. And when it comes to getting the band back together, it's a chance not just to relive the past, but to reunite in the present, to redeem what was lost, to restore what was broken, and maybe even receive something new for the future.

Now that could be quite a comeback.

Matt White is a Northern Irish TV producer living in Essex and working in London. Follow him on Twitter @mattgwhite