The Bible does not speak of spiritual illness, except in metaphorical terms. Spiritual sickness can be viewed as a lack of soundness of spirit caused by sin. Just as physical illness weakens the physical body, spiritual illness weakens the spirit. Unbelievers are “spiritually sick” because they are separated from the Lord and need a relationship with Jesus Christ. In fact, they are more than sick; they are dead “in trespasses and sins” ( Ephesians 2:1 ). Believers can also be spiritually sick in the sense that they are living in unconfessed sin or not seeking personal spiritual growth.
The Bible promotes what is spiritually nurturing as opposed to what would make us spiritually sick: “The fear of the Lord leads to life” ( Proverbs 19:23 ). And, “Surely the righteous will attain life, but he who pursues evil will find death” ( Proverbs 11:19 ). “Physical training is of some value,” Paul says, “but godliness is good for all things, having promise both for the present life and for the life to come” ( 1 Timothy 4:8 ). Piety, justice, and the fear of the Lord are the remedy for spiritual sickness.
Believers in Christ are taught the importance of “sound teaching” (Titus 2:1, NLT) and the danger of false and harmful teaching (1 Timothy 1:3–7). Paul points out that the goal of godly teaching is “love that comes from a pure heart, from a good conscience, and from sincere faith” ( 1 Timothy 1:5 ).
Jesus spoke of sickness in a spiritual context in Matthew 9:9–13. When Jesus dined at the home of a tax collector named Matthew, the Pharisees asked why he ate with such sinners. Jesus answered: “It is not the healthy who need a doctor, but the sick. But he sees and learns what this means: ‘Mercy I desire, not sacrifice’. For I have not come to call the righteous, but sinners” (Matthew 9:12–13). In this metaphor, Jesus compares himself to a doctor who had come to help the sick. Matthew was a patient who needed healing. Sickness was sin, and Jesus was the Healer; that is, Jesus can forgive sin and restore the spiritually sick. However, those who see themselves as “righteous”, those who, like the Pharisees, refuse to acknowledge their spiritual illness, deny their need for a spiritual Doctor and thus remain in their sin.
Spiritual illness can be closely related to physical and emotional illness. In Psalm 32, David writes of the impact his sick spirit had on other areas of his life: “My bones grow old through my groaning all day long. Because day and night your hand was heavy on me; my strength was spent as in the heat of summer” (verses 3–4). He also describes the path to wholeness: “Then I confessed my sin to you and did not cover my iniquity. I said, ‘I will confess my transgressions to the Lord.’ And you forgave the guilt of my sin” (verse 5). And David rejoices in the freedom that spiritual health brings: “Blessed is he whose transgressions are forgiven, whose sins are covered. Blessed is he whose sin the Lord does not take into account and in whose spirit there is no deceit. . . . Rejoice in the Lord and be glad, you righteous; Sing, all you upright in heart! (verses 1–2, 11).
God wants us to be spiritually healthy. He wants us to live in his forgiveness, free from the penalty of sin, the power of Satan, and the accusations of a guilty conscience. “May God himself, the God of peace, sanctify you wholly. May your whole spirit, soul, and body be preserved blameless at the coming of our Lord Jesus Christ” (1 Thessalonians 5:23). Any spiritual disease or sickness of the soul has at its root a sin in the heart that must be confessed to the Lord, who promises to forgive ( 1 John 1:9 ). God’s will is that we “grow in the grace and knowledge of our Lord and Savior Jesus Christ. To him be the glory now and forever! Amen” ( 2 Peter 3:18 ).