How do we know if God is giving us a disease because of our sins?

Answer:

One of the mistakes Job's friends made was to assume that his suffering was due to his personal sins.

• Eliphaz: "According to what I have seen, those who plow iniquity and those who sow trouble harvest it. By the breath of God they perish, and by the blast of His anger they come to an end" (Job 4:8-9).
• Bildad: "If you are pure and upright, surely now He would rouse Himself for you and restore your righteous estate" (Job 8:6).
• Zophar: "But would that God might speak, and open His lips against you, and show you the secrets of wisdom! For sound wisdom has two sides. Know then that God forgets a part of your iniquity" (Job 11:5-6).

But by the time we reach the end of the book of Job, we learn that Job's friends were wrong. "It came about after the LORD had spoken these words to Job, that the LORD said to Eliphaz the Temanite, "My wrath is kindled against you and against your two friends, because you have not spoken of Me what is right as My servant Job has. Now therefore, take for yourselves seven bulls and seven rams, and go to My servant Job, and offer up a burnt offering for yourselves, and My servant Job will pray for you. For I will accept him so that I may not do with you according to your folly, because you have not spoken of Me what is right, as My servant Job has." So Eliphaz the Temanite and Bildad the Shuhite and Zophar the Naamathite went and did as the LORD told them; and the LORD accepted Job" (Job 42:7-9).

In Psalms 38, David pleads with God not to punish him out of anger. David would not survive if that happened. As it was, David was heavily burdened and he knew that it was due to his own sins. "There is no soundness in my flesh because of Your indignation; there is no health in my bones because of my sin. For my iniquities are gone over my head; as a heavy burden they weigh too much for me. My wounds grow foul and fester because of my folly" (Psalms 38:3-5). Most assume that this Psalm was written when David was running from Absalom. "My loved ones and my friends stand aloof from my plague; and my kinsmen stand afar off. Those who seek my life lay snares for me; and those who seek to injure me have threatened destruction, and they devise treachery all day long" (Psalms 38:11-12). His predicament was foretold to him by the prophet Nathan after he had committed adultery and tried to hide it by committing murder (II Samuel 11-12).

Unlike Job's friends who assumed Job had to have sinned, even though they had no evidence, David knew he had sinned and he knew that God stated that he would be punished for it. In some ways, David's sufferings were due to his knowledge of how badly he had sinned. He fell into depression. "I am bent over and greatly bowed down; I go mourning all day long. For my loins are filled with burning, and there is no soundness in my flesh. I am benumbed and badly crushed; I groan because of the agitation of my heart. Lord, all my desire is before You; and my sighing is not hidden from You. My heart throbs, my strength fails me; and the light of my eyes, even that has gone from me" (Psalms 38:6-10).

David did not turn from God, but rather it was because of his desire to follow God that these things had such a strong impact in his life. Psalms 38 expresses the sorrow that sinners should have that leads to true repentance. "For the sorrow that is according to the will of God produces a repentance without regret, leading to salvation, but the sorrow of the world produces death. For behold what earnestness this very thing, this godly sorrow, has produced in you: what vindication of yourselves, what indignation, what fear, what longing, what zeal, what avenging of wrong! In everything you demonstrated yourselves to be innocent in the matter" (II Corinthians 7:10-11).

Therefore, just because you are ill, it does not necessarily mean that you are being punished for some sin that you have committed. But there may be times that you knew you sinned and the sufferings you are currently enduring are a result, such as a fornicator dealing with a venereal disease.