Christian theology is talking and writing about the triune God (Father, Son, and Holy Spirit). It has a history of two thousand years. There are multiple traditions: Catholic, Eastern Orthodox, Protestant, Reformed, Liberal, Evangelical, Feminist, Black, Liberation, Conservative...
There are multiple sub-disciplines of theology: Biblical, Old Testament, New Testament, Trinitarian, missional, spiritual, historical, pastoral, practical, political, ...
There are multiple topics: Trinity, creation, sin, redemption, revelation, the Cross, the Incarnation, soteriology, ecclesiology, Christology, eschatology,...
Denominations, churches, parachurch ministries, and careers are often built on making one of these theologies central and dominant.
There is endless jockeying and competition within the church and the academy for the relative importance and priority of one of these theologies. Fashions come and go. The "breakthrough" or "paradigm" of yesterday is today seen as a mistake or irrelevant or simplistic... However, it is amazing how in the long run people keep coming back to something basic that centres around the Bible and the theology of the early church, such as in the Apostles Creed.
Different factions critique one another, sometimes carefully and graciously. Sometimes critiques are harsh, aggressive, dogmatic, selective, and ill-informed. People talk past one another. Individuals and groups and their voices get marginalised within certain communities if they do not conform to the favoured "theology".
How do we make sense of all these competing voices?
Much of the difference between these theologies is of emphasis. One particular topic, concept, method, perspective, Biblical passage, doctrine, creed, or historical figure is claimed to be the most important and to provide the key to making sense of everything else. The problem is whether the emphasis is helpful overall or whether the emphasis distorts the overall picture in an unhelpful way.
Where does this diversity come from?
We should not be surprised by this diversity of perspectives and emphases as the diversity reflects the nature of the object under study and the nature of the subject studying it.
The objects under study are God, humanity, the world, and their interplay. This is a multi-faceted reality. The complexity of these objects requires descriptions at multiple levels and perspectives. This leads to a multiplicity of questions, methods, and conclusions.
Just consider the Bible. It has multiple authors, and possibly editors, who wrote in diverse contexts over two thousand years. There is a multiplicity of genres: history, law, poetry, prophecy, pastoral letters, and apocalyptic. How is this canon of literature to be interpreted? Naturally, the text will mean different things to different people at different times and in different contexts. The text does not interpret itself. Readers will interpret the text drawing on a complex interplay of interplay of reason, experience, and tradition. Even interpreters who claim to be drawing on a specific tradition have to also interpret that tradition. Given our diversity of personalities, life histories, and contexts it should not be surprising that we disagree about questions of meaning and significance on the most profound topic of all: God.
Everyone is a theologian. We are all human and this means that our theology is constrained by our limitations, individually and corporately. On the one hand, human language is incredibly powerful and a testament to what makes humans different from other animals. On the other hand, language, particularly formal academic language, cannot fully capture complex and subtle realities. That is why we have poetry!
Given our finite mental and linguistic capacities we need simplicity. This leads us to develop models, metaphors, frameworks, doctrinal statements and creeds. All models are wrong, but some are useful.
Theologies can reflect the fallen nature of humanity. Our reason and communication are corrupted by sin. This can lead to the narcissism of small differences. Eugene Peterson says "a sect is a front for narcissism."
What do we really need?
Humility, grace, and love. We need to be humble about our own abilities, individually and collectively, to discern the truth. We need to be gracious towards those who have different views. We need to be driven by love, love for God and love for others.
That there is a plurality of theologies does not mean they are all equally valid. On the one hand, we should not deny subjectivity. On the other hand, a careful comparison and critique of theologies different to our own may show their respective limitations. Commonalities that transcend our contexts may be a signpost to the essential truths to emphasise. Our focus should be on being more faithful to the centre, rather than trying to determine and enforce the boundaries of acceptable belief.
We need dialectic. A problem with many theologies is that they are dualistic. They are either/or. They embrace false dichotomies. There is room for both/and. Consider the following pairings: the humanity and divinity of Jesus, free will and predestination (human agency and God's sovereignty), faith and works, grace and judgement, redemption now but not yet, creation and fall (humans being made in the image of God versus corrupted by sin), faith and reason, special and general revelation, ... They need to be held in creative tension. Finding such a balance is impossible to do perfectly. But it is necessary if we are to be faithful to our subject.
Balance and emphasis are the impossible but necessary tasks of theology.