Truth, Faith, and Knowledge: Why We Can Trust God

Part Two in Our Apologetics Series: Building a Rational Faith

Last week, we explored the reality of truth, establishing that it exists independently of our opinions or feelings. Truth is objective, and it is essential: without it, life, reasoning, morality, and even human relationships would be incoherent. Today, we move forward with the question: If truth exists, where does it come from, and why is it reasonable to trust it?

The answer is profoundly foundational to both apologetics and discipleship: truth ultimately comes from God. Our confidence in God’s character undergirds a rational faith and provides a basis for trusting in what we know to be real.

Connecting Last Week: The Reality of Objective Truth

Last week, we examined the nature of truth. We saw that objective truth is necessary for life to make sense. Without truth:

• Reasoning would be impossible—logical principles like “if A = B and B = C, then A = C” would have no meaning.

• Morality would be arbitrary—statements like “hurting someone is wrong” would have no universal weight.

• Knowledge itself would be suspect—if reality were not consistent, learning or science would be futile.

This foundation sets the stage for our current question: Where does truth come from? To answer it, we examine the consistency of the world around us and the rationality of expecting that consistency to continue.

Concrete Examples: Truth in the Everyday World

We rely on patterns and constants in daily life, often without thinking. Consider:

• Water always boils at a particular temperature.

• Gravity reliably pulls objects toward the Earth.

• Mathematics functions predictably—2 + 2 = 4, every time.

Why do we expect these phenomena to behave consistently? Why can a chemist in Cleveland rely on the same chemical principles as a chemist in Tokyo? Why can a child trust that stepping off a curb will not violate the laws of physics?

The answer is that reality is grounded in an unchanging, rational foundation. The uniformity of nature, the consistency of logic, and the universality of moral law point to a perfect, unchanging, and rational source: God. Without such a source, there would be no ultimate reason to trust that reality will behave consistently.

God is the reason we can expect the world to be dependable.

This principle is not only philosophical, it is deeply practical. It forms the basis for rational knowledge and the foundation upon which faith can stand.

Making the Case for God

God’s perfection, constancy, and rationality provide a foundation for multiple dimensions of truth:

1. Natural Laws: God ensures that nature behaves consistently—water always boils at 100°C at sea level, gravity consistently exerts force, and stars follow predictable orbits.

2. Mathematical and Logical Reliability: Logic is universal because it reflects God’s unchanging rationality. Principles like non-contradiction (something cannot both be and not be) depend on God’s mind as the ultimate standard.

3. Moral Laws: Right and wrong are not arbitrary; they derive their authority from God’s character. Humans recognize injustice, cruelty, or mercy because these align—or misalign—with the moral order God has established.

4. Epistemic Trust: Our very ability to know anything presupposes a dependable reality, which God guarantees.

Without God, there is no ultimate reason to trust that reality will remain consistent, that logic will hold, or that morality has any binding authority.

Real-Life Scenario: The Parachute Analogy

Faith is often misunderstood as believing without reason. Yet, in practice, we trust all kinds of things every day. Imagine preparing to skydive. You are given a parachute and told it is safe. In a real sense, you are placing your life in the parachute.

Now consider two scenarios:

1. The parachute looks sloppy, old, and untested. No one knows who packed it, and ten previous jumpers have tragically fallen. Would you jump? Likely not.

2. The parachute is expertly packed by the world’s leading parachute technician, with a flawless track record. Suddenly, trusting the parachute is reasonable.

Faith in Christ is analogous. God is perfectly faithful and trustworthy. Our confidence is grounded not in wishful thinking, but in the reliability of His character and promises. Just as a parachute earns our trust through competence and proven reliability, God earns our trust through His unchanging nature.

Faith is trust, but it’s trusting big—our lives often depend on it.

Truth: Absolute and Knowable

Christianity asserts a number of universal truths: “God exists,” “God created the universe,” “the Bible is God’s Word,” “Jesus rose from the dead,” “the Holy Spirit is God.” These truths are not subjective—they are absolute, true for all people, at all times.

Modern culture often promotes relativism—the view that truth is personal, varying from one individual to another. A relativist might claim, “The statement ‘God exists’ is true for you, but not for me.”

The problem, however, is an internal contradiction. Relativism itself is presented as an absolute truth: “There is no absolute truth.” If true, this statement refutes itself. The very act of claiming relativism assumes some truths are universal, revealing the incoherence of the position.

Truth, therefore, is correspondence to reality: something is true if it matches how the world actually is. “Snow is white” is true only if snow is white. Moral truths are similarly grounded in God’s character: harming others is wrong because God’s nature is holy and just.

Christianity is not just a collection of true statements—it is a framework for trusting and living within reality itself.

Faith: Beyond Belief

Hebrews 11:1 defines faith as:

“The assurance of things hoped for, the conviction of things not seen.”

Faith involves two elements:

• Assurance and Conviction: Our minds are set; we are certain of what we trust.

• Hoped For, Not Seen: Faith operates beyond our immediate control.

Faith is not a casual agreement with facts—it is a deep, active trust in God’s promises. Using the parachute analogy, faith is knowing the chute will open even though the outcome is unseen. Trusting God is living as if His promises are real, even when circumstances are uncertain.

Rational faith is faith informed by knowledge, evidence, and reason. Faith is not irrational—it is confidence grounded in God’s unchanging nature and the truths He reveals.

Knowledge: Strengthening Faith

Knowledge enhances faith by providing reasons to trust God. Abraham’s example in Genesis 22 is instructive. God asked him to sacrifice Isaac, an unimaginable request. Yet Abraham went

forward, confident in God’s faithfulness. Why? Because Abraham had observed God’s trustworthiness over time:

• God had fulfilled promises in Abraham’s life, especially regarding Isaac’s birth.

• God’s covenant demonstrated unwavering fidelity.

Abraham’s faith was rational. It did not disregard reason or evidence; it was strengthened by knowledge of God’s past faithfulness. Knowledge and revelation produce rational, confident faith rather than opposing it.

Knowing God and His faithfulness makes faith reasonable.

The Gospel Connection: Truth, Knowledge, and Faith United

Romans 3:21–26 illustrates the interplay of truth, knowledge, and faith in the gospel:

1. Truth: “For all have sinned and fall short of the glory of God.” The reality of sin is universal.

2. Knowledge: God has revealed Himself through Scripture and fulfilled His promises in Christ. We can know the plan of salvation and the character of the Savior.

3. Faith: Jesus’ death and resurrection provide justification. Faith is the confident trust that Christ’s work secures our salvation.

Faith is not blind; it is trusting a reliable Savior whose promises are backed by truth and historical reality.

Truth isn’t relative, knowledge isn’t uncertain, and faith isn’t blind.

The gospel provides the ultimate assurance. We place our trust in God because He has revealed Himself faithfully, acted decisively in history, and offers reconciliation through Christ.

Integrating Truth, Knowledge, and Faith into Discipleship

Understanding the connection between truth, knowledge, and faith equips us for a life of discipleship:

• Truth as the foundation ensures our beliefs align with reality.

• Knowledge of God’s character and past faithfulness strengthens confidence in following Him.

• Faith applied to life moves us to trust, obey, and live out God’s commands in tangible ways.

Our discipleship is not merely about internal belief; it is about living confidently in the reality God has established, trusting Him even in uncertainty, and making rational, informed commitments to follow Christ.

Conclusion: Why Trust in God Is Rational

Objective truth exists, and it requires a stable source. God, as perfect, rational, and unchanging, is the foundation of that truth. Faith in Him is rational, informed by knowledge, and grounded in the reality He reveals. The gospel unites truth, knowledge, and faith, calling us to respond confidently to the work of Christ.

Our trust is not based on wishful thinking or societal consensus; it is anchored in:

• The unchanging nature of God

• The reliability of His revelation

• The historical reality of Christ’s work

This is not blind faith. It is a confident, informed, and reasonable trust that God is who He says He is and that His promises are true. Living as a disciple requires embracing this foundation and allowing it to shape our choices, values, and actions every day.

Credits and References

• Teaching inspiration: The Making Disciples Curriculum from faculty at Southwestern Seminary