What if your grandmother were to develop flu-like symptoms about a month after receiving her flu shot? Would you say, "Grandma, you can't have the flu. You just got your flu shot last month."

What if her doctor also said, "She does have the classic flu symptoms, but she cannot have the flu because I gave her a flu shot"? And what if your grandmother herself refused to believe that she could have the flu because she had received the inoculation?

Your grandmother's flu-like symptoms should influence your response to the situation far more than anyone's assumptions about the effectiveness of the flu shot.

While only some people get the flu, every person has a much bigger problem. And it is no mere illness. Everyone is born spiritually dead (Psalm 51:5; Eph. 2:1-3). It is a willful, sinful deadness that offends God and demands His just punishment. And it too has evident symptoms.

Without a microscope you cannot see the virus that causes the flu. But you can notice its effects on the body—fever, chills, aching bones, etc. Only God can see the heart of the spiritually dead person (the one who has not been born again), but everyone can see what flows from it. As Jesus said:

For from within, out of the heart of man, proceed evil thoughts, fornications, thefts, murders, adulteries, deeds of coveting and wickedness, as well as deceit, sensuality, envy, slander, pride, and foolishness. All these evil things proceed from within and defile the man (Mark 7:21-23).

Now here is the question I want you to ponder: What if a person who says he has been born again still displays the symptoms of a dead, unchanged heart? In other words, he says he has "received Jesus," "made a decision for Christ," or "invited Jesus into his heart" yet shows no signs of having been cured. Would you just assume that he is saved because he says he has been "inoculated"? Can you rightly consider him to be "born again," even though he consistently thinks, speaks, and acts just like the people who make no such claim?

Consider some of the following "symptoms"—patterns of thought and behavior that the Bible says do not characterize the true Christian:

• Denial or serious distortion of essential biblical truths (such as the deity of Christ, His bodily resurrection, justification by faith alone, etc; Gal. 1:8-9; 2 Pet. 3:16; 2 John 9).
• Lack of love for Christ. This is often seen in ongoing patterns of disobedience to Him (John 14:15; 1 John 2:3-4; see 1Cor. 16:22). True Christian obedience (as opposed to mere moral behavior) flows from heart—felt affection for Christ.
• Disinterest in God's Word. The Bible is the revelation of God Himself (John 5:39). The person who has no interest in the Bible has no interest in God (see Ps. 138:2).
• Lack of love for other Christians (1 John 2:9-10; 3:10). For example: The person who abandons Christian fellowship altogether, or the one who remains formally "connected" through church membership but does not participate in regular, active fellowship with other believers, does not truly love them.
• Pride (Prov. 6:16-19; 8:13; Luke 18:10-14). This is commonly seen in eagerness to dwell on the sins of others, while being reluctant to confess personal sins and seek forgiveness.
• Unforgiveness (Matt. 6:14-15; 18:21-35).
• Fornication, adultery, or any other form of sexual immorality (Eph. 5:5; 1 Cor. 6:9-10).
• Covetousness—the pursuit of money, material things, or other forms of gratification in a way that reveals idolatry in the heart (1 Cor. 6:10; Eph. 5:5; Col. 3:5; 1 John 2:15-16).
• Habitual outbursts of anger (Gal. 5:19-21).
• Drunkenness or other forms of chemical addiction (Gal. 5:21).

Should we take comfort in the fact that some of our friends or family members have received their "gospel flu shot" and naively consider them safe and well, even though they consistently display classic symptoms of spiritual deadness—attitudes and actions the Bible repeatedly says are characteristic only of people who are unsaved and going to hell? Or should their symptoms cause deep concern and prompt us to become lovingly involved?