Latter-day Saints often love to point to Jesus’s words about recognizing a prophet “by their fruits.” They highlight statistics like lower divorce rates or higher rates of charitable giving and claim that these outcomes prove Joseph Smith was a true prophet. But is that really what Jesus had in mind? And is that the only relevant test that the Bible gives us?
In a recent sermon, my pastor drew from a framework developed by John Piper, outlining four biblical “tests” for discerning true and false teaching:
1. The Fruit Test – Does the teacher’s life display godly character? (Matthew 7:15–20)
2. The Doctrine Test – Do they teach the truth about Christ and His divine nature? (1 John 4:1–3)
3. The Scripture Test – Do they submit to God’s Word? (1 Corinthians 14:37; 1 John 4:6)
4. The Gospel Test – Do they preach salvation by grace through faith alone? (Galatians 1:8–9)
If we ignore any of these tests—especially if we rely only on one—we open ourselves to spiritual deception.
The Appeal and Danger of the Fruit Test
From an LDS perspective, the proof of the “restored gospel” is found in its visible results: strong families, clean living, charitable service, missionary zeal, and social cohesion. These are admirable traits, and on the surface they seem to confirm Jesus’s statement that “by their fruits you shall know them.”
But Jesus’s warning in Matthew 7 isn’t about identifying which religion appears most moral. It’s a call to look beneath appearances—to discern whether the root is truly connected to Him.
The Pharisees of Jesus’s day were outwardly righteous but inwardly proud and blind. They were “whitewashed tombs” whose fruit looked good to everyone except God. If you had asked them about their fruit, they would have pointed to their charity, their study of Torah, and their devotion to religious law. They were admired for their piety—but their fruit was self-grown, not Spirit-grown. It sprang from pride and self-righteousness, not grace. Such fruit cannot lead to a living, life-giving relationship with God.
I don’t mean to suggest that this describes all Latter-day Saints. Far from it. But Jesus’s warning about the Pharisees should make us cautious about relying solely on outward morality. We must not confuse moralism or religious devotion with the true fruits of the Spirit.
Indeed, when we focus too much on outward fruit, we become especially vulnerable to deception. Satan does not mind highly moral systems; he often uses them. Such systems can either puff people up with pride or crush them with guilt. Paul warns that “even Satan disguises himself as an angel of light” (2 Corinthians 11:14). The most effective counterfeit is not open evil but a religion of impressive virtue that subtly denies the sufficiency of Christ.
That’s why the other three tests are so vital. They ensure that the fruit we see grows from a living faith in the true Christ.
The Doctrine Test – Who Is Jesus?
1 John 4 tells us to “test the spirits” by their confession of Christ. A teacher may promote family values or upright behavior, but if they redefine Jesus—denying His eternal deity or making Him one among many divine beings—they have already failed the most important test.
Jesus said that He is the vine and we are the branches (John 15:5). If we are not connected to the true vine, no matter how good our fruit appears, it will wither. Simply put, you cannot have true fruit from a false Christ.
The Scripture Test – Who Holds Authority?
True teachers submit to God’s written Word. They don’t add new revelations that override it, nor do they reinterpret it to fit a new theological system. Even the devil can quote Scripture—but he never submits to it.
The LDS system of modern prophets and continuing revelation turns this test upside down. Rather than sitting under the Word, leaders place themselves above it, treating Scripture as flexible and incomplete. Once you do that, any doctrine can be justified. Submission to the Word is replaced by submission to men.
The Gospel Test – What Saves?
This is the most crucial test of all. If we get the gospel wrong, nothing else we get right really matters.
Paul warns that if we follow another gospel, we “set aside the grace of God” (Galatians 2:21), and “Christ is become of no effect unto you” (Galatians 5:4). False teachers may advocate practices that have “an appearance of wisdom in self-imposed religion” (Colossians 2:23), but if their message adds works on top of the simple good news of grace through faith in Christ, it must be rejected.
Galatians 1:8–9 leaves no room for blending grace and works, or for adding temple covenants and ordinances as requirements for eternal life. Outward fruit may flourish in such a system for a time, but it cannot save, because it grows from self-effort rather than grace.
The Whole Picture
Paul’s words to Timothy summarize all of this: “You, however, have followed my teaching, my conduct, my aim in life, my faith, my patience, my love, my steadfastness” (2 Timothy 3:10). Both a faithful life and sound doctrine matter. True fruit flows from true teaching, grounded in Scripture and centered on the gospel.
Fruit matters—but fruit alone can deceive. The real question isn’t, “Does it work?” but “Does it lead me to the true Christ revealed in Scripture and to rest in His finished work of grace?”