What does Scripture teach about why some people claim to be Christians but do not love their neighbors as themselves, and how can we tell the difference between a true believer struggling with sin and someone who only professes faith outwardly?

Scripture teaches that some people claim Christ outwardly while remaining unchanged inwardly. Jesus warned that not everyone who says, “Lord, Lord,” truly belongs to Him, because the real test is not mere profession, but fruit, obedience, and love: “by their fruits you will know them” and “I never knew you” (Matt. 7:16–23). John says it even more plainly: “He who says he is in the light, and hates his brother, is in darkness until now” (1 John 2:9–11), and, “He who does not love does not know God, for God is love” (1 John 4:7–8). So one reason some people claim to be Christians and yet do not love their neighbors is that they are professors only, not possessors of genuine saving faith. They may have a form of godliness while denying its power (2 Tim. 3:5), honor God with their lips while their heart is far from Him (Matt. 15:8; Isa. 29:13), or hear the Word without truly doing it (James 1:22–25; Ezek. 33:30–32). In other words, the assumption that everyone who uses Christian language is actually born again is often false.

 

At the same time, Scripture also teaches that a true believer can still struggle with sin. Romans 7:14–25 shows the painful war that remains in the believer, and Galatians 5:16–17 says the flesh and the Spirit are contrary to one another. A real Christian is not sinless, and “if we say that we have no sin, we deceive ourselves” (1 John 1:8–10). But here is the difference: a true believer does not make peace with sin. He is grieved by it, confesses it, and is chastened by the Lord (Ps. 32:3–5; Prov. 28:13; Heb. 12:5–11). He returns to Christ, not away from Him. His life shows some real fruit of the Spirit—love, joy, peace, longsuffering, kindness, goodness, faithfulness, gentleness, and self-control (Gal. 5:19–24)—even if imperfectly and progressively. Scripture says, “By this we know that we know Him, if we keep His commandments” (1 John 2:3–6), and again, “By this all will know that you are My disciples, if you have love for one another” (John 13:34–35). So the mark of a true believer struggling with sin is not flawless performance, but repentance, chastening, growth, and a real pattern of love and obedience produced by abiding in Christ (John 15:1–6; Phil. 2:12–13; 2 Pet. 1:5–11).

 

By contrast, someone who only professes faith outwardly may speak well, look religious, and even associate with the church, yet remain fruitless, self-serving, divided in heart, and unchanged at the core. Scripture describes such people as “whitewashed tombs” (Matt. 23:27–28), branches that do not abide in the vine (John 15:1–6), hearers choked by cares, riches, and pleasures so that they “bring no fruit to maturity” (Matt. 13:18–23; Mark 4:16–19; Luke 8:13–14), and those who “profess to know God, but in works they deny Him” (Titus 1:16). Their pattern is not stumbling and repenting, but practicing lawlessness, excusing sin, lacking mercy, and showing little or no evidence of brotherly love (1 John 3:10, 14–15; Matt. 25:31–46; James 2:14–17; 2 John 5–6). So the difference is this: the true believer may fall, but he does not settle there; he is corrected, convicted, and drawn back to Christ. The false professor may speak the language of faith, but his heart remains unbroken, unyielded, and unfruitful. That is why Scripture tells us not merely to listen to claims, but to “examine yourselves as to whether you are in the faith” (2 Cor. 13:5), because the Lord does not see as man sees—He searches the heart and gives to each according to his works (1 Sam. 16:7; Jer. 17:9–10; Rev. 2:23).