Real Questions. Honest Answers Series – Week 3

Week 3: Why Are Things Not Explicitly in Scripture Required to Be Saved?

"Why are things not explicitly in Scripture required to be saved? For example, we say you must believe the Trinity to be saved, but that word isn’t in the Bible."

This thoughtful question gets at two important issues: (1) How do we define what’s “explicitly” in Scripture? and (2) What’s the difference between not understanding something and actively denying it? These are good distinctions to make, and how we answer them matters.

Summary Answer

Salvation is not about checking off a list of doctrinal phrases, it’s about trusting in the God who actually exists and responding to the truth He has revealed. While the Bible doesn’t list doctrines in order of importance, it makes clear that who you believe in and what you trust Him to do are vital. Some truths are so central to the gospel that denying them means you're no longer trusting in the God of Scripture even if your words sound Christian.

Part 1: Why Are Some Doctrines Required for Salvation If They’re Not Explicitly in Scripture?

The Bible never says, “Here are the 5 doctrines required for salvation.” But it does say:

• Some truths are of first importance (1 Corinthians 15:3–4)

• Some errors lead to destruction (2 Peter 2:1–3)

• Some teachings are so central to the gospel that to deny them is to lose the gospel itself (Galatians 1:6–9)

So how do we make sense of this?

A. The issue is not wording but meaning

Scripture may not use the words Trinity, hypostatic union, or penal substitution but it clearly teaches those ideas. What matters is whether we affirm the truth the Bible teaches, even if it’s described using later theological language.

A person might not use the phrase “justification by faith,” but if they believe Jesus’ death alone makes them right with God they’re trusting the right gospel. But if they deny that truth, even while calling themselves a Christian, they’re trusting something else.

B. Not understanding vs. knowingly rejecting

This is key:

• Immaturity, ignorance, or newness in the faith is not the same as hard-hearted rejection.

• Many are saved with incomplete knowledge, but those who persist in rejecting essential truths are not worshiping the God of the Bible.

C. Summary

We don’t add extra requirements to the gospel. But we must also avoid shrinking the gospel to a handful of generic statements. God has revealed Himself and trusting Him rightly means submitting to what He’s shown us.

Part 2: Case Study: The Trinity

Let’s now look at the example in the question: Is belief in the Trinity required to be saved?

Short answer:

You don’t need to fully understand the Trinity to be saved, but knowingly rejecting it is rejecting the God of Scripture.

1. The Trinity is taught throughout Scripture

• One God (Deuteronomy 6:4)

• Father is God (John 6:27)

• Son is God (John 1:1–14; Colossians 2:9)

• Spirit is God (Acts 5:3–4)

• Three persons interacting (John 14:16–17; Matthew 28:19)

The Bible doesn’t use the word Trinity, but the truth of one God in three persons is unmistakably present.

2. The early church worshiped a Triune God before defining the doctrine

• They baptized in the name of the Father, Son, and Spirit

• They prayed to the Father, through the Son, in the Spirit

• They confessed Jesus as Lord (Philippians 2), a title used of Yahweh in the Old Testament

They didn’t yet have technical language—but they believed and worshiped the Triune God.

3. Heresy led the church to clarify, not invent

False teachers like Arius denied Jesus was fully God. This forced the church to ask: What does the Bible actually say?

• Ignatius of Antioch (early 2nd century) spoke of Jesus as God.

• Justin Martyr (mid-2nd century) described the Son and the Spirit as divine.

• Irenaeus (late 2nd century) defended the unity and divinity of Father, Son, and Spirit.

• Tertullian (early 3rd century) used the Latin word “Trinitas” to describe the unified Godhead.

Church Councils:

• Council of Nicaea (AD 325): The Son is of the same essence as the Father (homoousios)

• Council of Constantinople (AD 381): The Spirit is fully God and personal

These councils didn’t invent the Trinity, they defended what was already taught in Scripture and practiced in the church. Early Christians didn’t need the word “Trinity” to be saved. But once the doctrine was made clear, to reject it knowingly was to reject the faith itself.

4. Why this doctrine matters

The Trinity shapes every part of salvation:

• The Father plans

• The Son accomplishes

• The Spirit applies

Without the Trinity, the gospel falls apart. So again: not everyone needs to fully articulate the Trinity to be saved. But those who persist in denying it are rejecting the very identity of the God who saves.

As Michael Reeves writes, “The Trinity is not the awkward math problem of our faith—it’s the good news. It’s the beauty and joy and life of the gospel.” We believe in a God who is love—and love is relational. God has always existed as a community of love: Father, Son, and Spirit.

To knowingly deny the Trinity is to deny God’s self-revelation. And trusting a different god, one who is not Triune, is not saving faith. It is to trust a god who cannot save.

Key Scriptures

• Matthew 28:19 – Baptize in the name of the Father, Son, and Holy Spirit

• John 1:1, 14 – The Word was God… the Word became flesh

• 2 Corinthians 13:14 – The grace of Jesus, love of God, and fellowship of the Spirit

• Galatians 1:6–9 – Warning against false gospels

• Colossians 2:9 – In Christ the fullness of deity dwells bodily

Recommended Resource

Delighting in the Trinity by Michael Reeves. This book is short, fun to read, and incredibly helpful. It explains why the Trinity isn’t just a doctrinal box to check, it’s the heart of the Christian faith. Great for teens, new believers, and anyone wanting to know God better.