I'm very tribal, and have enjoyed tribalism in the past, but have become disenchanted with it for some of the following reasons:
Tribalism fails to deliver what it promises
Each tribe promises something. When I was in the Pentecostal tribe it promised success and good health, but I had a disability. When I was in the Charismatic tribe it promised revival, but it never came. When I joined the Reformed tribe it promised theological correctness, but there's been plenty of doctrinal and practical incorrectness. When I joined the Independent tribe, it was the promise we can do more together and help council estate ministry, but this happened. I wonder why we make these promises? Is it a way to recruit and retain people to join our tribe and justify our tribalism? Have we accidentally placed our Tribes as the new messiah who offers the things that only Christ can deliver?
Tribalism entrenches our blindspots.
God's Church is so broad with so many facets, but our tribes will usually only ever link up with a handful of tribes closest to us. This can give us the false impression of broadening our horizons, whilst reinforcing the blindspots that our similar tribes will never expose.
Tribalism gives a false view of God's Church.
One the one hand, we occasionally say that God's Church includes all believers saved by faith in Jesus throughout all time: But on the other hand, our tribalism communicates that we are the only true believers. Again, we might give head nods to the other tribes closest to us, but we still exclude so many others. How do we pray Ps 14:7? Is it for all God's tribes, or just our own?
Tribalism wastes resources.
We plant churches on the doorstep of other churches because they're not in our tribe. We think God wants more of our tribe (even if its only existed a few years), not more of His Church (which has lasted for millennia). We ignore the locations that don't have a church, and instead, we double up, triple up, quadruple up churches in well-resourced places, because we think they need our tribe.
Tribalism misses out on partnerships made in heaven (literally).
Personally, I've been more blessed by people outside my tribe than in! Maybe this was God's ways of opening my eyes to the foolishness of sticking my own tribe.
Tribalism falsely thinks God only started ministry with you.
If a tribe decides to do something, like 'refugee ministry', it will start to talk about a new thing that God is doing. It will ignore others from other tribes who have been doing this ministry for years.
Tribalism boost self-righteousness.
I feel superior to others because my tribe has got it right. I trust in my tribe's way of doing things, rather than Jesus' righteousness. As a Pentecostal, we had the Power, as a Charismatic, we had the Spirit, as Reformed, we had the Doctrine, as Independents we had the Polity.
Of course, as an anti-tribalist now, I can also be self-righteous, looking down on those who are tribal (even whilst I still deep down hold to tribalism in many ways)!
What's the answer?
1) I think we need a bigger understanding that the mission is Jesus' mission. He started it, and he's been doing it for years, through various different groups all over the world. Its about His mission, not ours.
2) I think we need a bigger vision of Christ's righteousness, because the more I truly am content with His record of right, the lest I'm gonna desire to be right in my tribe that's supposedly got it all right! The more humble, I'll be with other brothers and sisters from different tribes, and the more I'll exalt them in my eyes as I realise they too are clothed with Christ's rightness.