The Christian Family Tree

One Family, Many Branches

If you have ever driven through an ordinary American town, you have seen it: a Baptist church on one corner, a Catholic parish down the street, a Methodist congregation across from a Presbyterian one, a Pentecostal storefront, an Orthodox church with its distinctive dome, a non-denominational congregation meeting in a school gym. To an outsider it can look like chaos, or like proof that Christians cannot agree on anything. To a new believer it can be bewildering: which one is the real one? But there is a better way to see it. What looks like a scattered crowd of competing brands is, more truly, a single enormous family tree — one trunk, many branches, grown over two thousand years.

That is the picture this course will hold in front of you. Not a battlefield with a winner to crown, and not a shapeless blur where the differences do not matter, but a family — with a common trunk that genuinely unites, and real branches that genuinely differ. In Rooted you learned to sort differences into tiers: the essentials that define the faith, the convictions where sincere believers land differently, and the other faiths that begin from a different foundation altogether. Almost everything in this course lives in that middle tier. These are, overwhelmingly, disagreements within the family — between brothers and sisters who share the trunk.

²⁰ “My prayer is not for them alone. I pray also for those who will believe in me through their message, ²¹ that all of them may be one, Father, just as you are in me and I am in you. May they also be in us so that the world may believe that you have sent me.John 17:20-21 · NIV

On the night before he died, Jesus prayed for us — for everyone who would ever believe through the apostles’ message. And what he asked for was unity: "that all of them may be one." It is worth sitting with the fact that Christian oneness was Jesus’ own farewell prayer. That prayer both comforts and convicts. It comforts, because it means the unity of the church rests finally on him and not on us. It convicts, because our divisions are not something to shrug at — they grieve the heart of the one who prayed that we would be one, so that the world would believe.

The Trunk: What the Whole Tree Shares

Before we look at a single branch, we have to see the trunk — because the branches only make sense as branches of something. Catholics, Orthodox, and the whole Protestant family hold an astonishing amount in common, and it is precisely the most important things. They confess the same Triune God: Father, Son, and Holy Spirit. They confess Jesus as fully God and fully man, crucified for sinners and bodily raised. They read the same core Scriptures as the inspired Word of God (Catholics and Orthodox also receive several additional Old Testament books that Protestants set apart as the Apocrypha). They pray the same Lord’s Prayer. For roughly fifteen centuries the church summarized this shared faith in the great ecumenical creeds — above all the Nicene Creed, which East and West alike still confess. (The Apostles’ Creed, treasured across the Western branches, is Latin in origin and is not used in the Eastern Orthodox liturgy.) To this day Christians of nearly every branch can recite the Nicene Creed together and mean it.

This is the point most arguments forget. When a Baptist and a Catholic and an Orthodox believer recite the Nicene Creed, they are not being vague or diplomatic; they are naming the actual trunk of the tree. The differences we will study are real and sometimes weighty, but they are differences among people who share that creed. Keeping the trunk in view is what will let us look honestly at the branches without turning family members into enemies.

The shared trunk — held across the branches:

Why the Branches Grew

If the trunk is so strong, why are there so many branches? Part of the answer is sin — pride, politics, power, and stubbornness have all split churches that never needed to split, and we should be honest about that. But that is not the whole story, and it would be unfair to pretend it is. Branches also grew because sincere believers, reading the same Bible, reached different conclusions about real questions: How should a church be governed? What happens at the Lord’s Supper? Who should be baptized, and how? How do God’s grace and our response fit together? These are not silly questions, and Scripture does not answer every one of them with a single unmistakable sentence. Good people, praying hard and studying carefully, have landed in different places.

So this course will do two things at once, and you will feel the tension. It will take the differences seriously — we will not pretend a Presbyterian and a Pentecostal believe the same thing about the Spirit’s gifts, because they do not. And it will take the family seriously — we will represent every branch the way its own faithful members would, so fairly that they would nod and say, "yes, that is why we believe it." That double posture is the skill Rooted handed you, and it is the whole discipline of this course.

Go deeper → This session names the shared essentials but does not unpack them — that is Rooted’s job. If you have not yet taken Rooted: Essentials, Liberty & Charity, start there; it is the on-ramp that teaches the three tiers this whole course depends on.

What Christian traditions have you actually lived near or inside — the church you grew up in, ones friends belong to, ones you have quietly judged from a distance? Where did your first impressions of "those other Christians" come from?

Read John 17:20-21 again slowly. If Jesus’ own farewell prayer was for our unity, how should that reshape the way you think and talk about Christians in other branches of the family?

Check Your Understanding

Anchor verse: "…that all of them may be one, Father, just as you are in me and I am in you… so that the world may believe that you have sent me." — John 17:21