Man's sin nature makes him prone to believing the error that he is able to please God unaided. Man's first sin was yielding to Satan's temptation "to be as gods," knowing, or determining for himself, what was good and what was evil. Man is thus inclined to believe he is as good as he can be and, perhaps, a little better than he needs to be. (Of course, men with such an attitude often are willing to allow themselves a little moral latitude now and then.) When a man feels he is able to please God, he tends to mete out what he thinks will satisfy God, but no more. Men who think they are "good enough" to please God essentially elevate themselves above God and dole out to Him what recognition and duty they deem sufficient.
Even God's children must guard against this "good enough" attitude. Though redeemed by the blood of Jesus Christ and empowered by His Spirit, we are still subject to the rebellious thinking and behavior of the rebels we once were. When we fail to think God's thoughts after Him in faithful obedience, we inevitably return to our patterns of lawless rebellion. We repeat the sin of Adam and Eve and try to "be as gods" determining for ourselves good and evil.
It is easy enough to think of overt sins as results of our sin nature. Yes, sometimes we justify our acts of sin if they seem small enough to be insignificant in our eyes. Such disobedience to God's law-word is certainly a frequent testimony to our desire to be gods. There is, however, a more common way in which we, as Christians, can exhibit a "good enough" attitude and expect God to accept our crumbs as noble deeds.
Christ addressed this very issue of "good" deeds, and to what extent they are praiseworthy before God, in the Sermon on the Mount at the beginning of His ministry. Christians often discuss the question of whether unbelievers can do any good thing before God, or whether all their good deeds are themselves sin in the eyes of God because of their own position as rebels in His eyes. However, it is perhaps more appropriate for Christians to recognize that even the good deeds of Christians may receive no reward from God. In the Sermon on the Mount, that is the more pertinent issue addressed by our Lord.
Christ spoke regarding three forms of piety (Mt. 6:1-18): charitable giving to the poor, prayer, and fasting. His words were a caution that we not lose our reward for acts of piety: "Take heed that ye do not your alms before men, to be seen of them: otherwise ye have no reward of your Father which is in heaven" (v. 1). The key words here are those that refer to being seen of men as the motive for acts of piety. The warning is clear. If our motive is recognition by men then we "have [our] reward" (v. 2). That is, the recognition we seek, the adulation, and the reputation as a doer of good is itself our only reward. We get no more from God.
Christ said the same of prayer. Those who make a show of their prayers already "have their reward" (v. 5). They have the esteem of men and the reputation of piety that they sought, but no more reward from God, not even for prayer.
Likewise, those who fast in public in order to let everyone know they are suffering for their piety get nothing in the way of reward from God (v. 16). Their reward is the image they cultivate in others.
Christ's message is clear. Do not do good deeds for recognition. Give to the poor in secret; pray in secret; keep your fasting a private act. In each act of piety, take care to avoid any confusion about your desire to make a show for the favor of men. If this is not done, God will not reward any acts of piety.
Even the most legitimate acts of piety must be done as service to God. God does not want to be our ulterior motive. If our motive is to serve God, we should perform our acts of piety before Him. If we serve God for any other reason, that reason shall be the source of our own reward. God does not want or accept our secondary motives.
This has a seemingly infinite number of applications.
If a child does his schoolwork so he can go out with friends on Saturday, that is his sole reward. To be praiseworthy before God, work must be done as unto the Lord.
If a man is faithful to his wife for fear of the shame to which an illicit affair would expose him, that maintenance of his public image is his sole reward. To be praiseworthy, faithfulness must be in terms of obedience to God.
If a wife obeys her husband because she gets tired of fighting, then whatever domestic tranquility her obedience provides is her sole reward. To be praiseworthy, obedience must be in terms of her submission to the marriage covenant and her vows to God.
If an employee works hard because he anticipates a raise, that monetary reward is the sum he can expect. To be praiseworthy before God, work must be an outgrowth of one's understanding of his duty before God.
If a church has as its purpose higher attendance, then increased numbers will be its sole reward. God sees our hearts and judges even our acts of piety and devotion. Those done out of any motive other than the honoring of our duty to faithfully obey our Heavenly Father receive no reward from Him.
If we stop and examine ourselves, perhaps we would find less cause to expect blessings from God than we think. Even if we do not intentionally expect God to be satisfied with what we dole out to Him, our acts of devotion often come in small, tardy increments.
The Good Deeds of Unbelievers
Still, the question of good deeds of an unbeliever will continue to arise. We might define a deed itself as good (as opposed to sinful) if it is in accordance with God's law. The problem is that this requires us improperly to abstract actions from individuals. As we can see from Christ's words in Matthew 6, not all "good" deeds are praiseworthy or rewarded by God. The deeds of the unbeliever can certainly not merit salvation. That would presume that Adam and Eve's "playing god" could circumvent God's righteousness. But if the unbeliever means to do the right thing in any particular instance he may at times do just that. That is, his act or decision may have been in conformity to the law of God. The deed may be the correct one, but not praiseworthy or rewarded, because we cannot abstract a deed from the moral status of the man. Not even the believer's good deeds are worthy of reward if they are done for the wrong reason.
The only acts of obedience or piety that God rewards are those done in faithful obedience to Him. Obeying God for any reason other than the fact that He is God and demands our obedience implies that there is merit or praiseworthiness in our actions themselves. Without the merit of Jesus Christ applied to us by His indwelling Spirit, there is nothing in what we do that is praiseworthy before God. In serving Him, therefore, we must have as our sole motive His praise and glory. Acts of piety are not to show what we are, they are to show who we know God to be. We must examine our motives; God does not always reward good.