While it is true that good deeds are rewarded in this world as well as in the next, a man must not trust in his deeds, but in God. It may seem strange that there is no reference in the Bible to reward in the hereafter. The reasons may be the following. Not knowing what the state of the soul is without the body, we could not understand the nature of future reward, and the statement of it in the Bible would not have been a sufficient inducement for the people of that time to follow the commandments. Or it is possible that the people knew by tradition of reward after death, hence it was not necessary to specify it. As knowledge of nature and of God leads to trust in him, so ignorance leads away from it. It is as with a child, who develops in his manner of trusting in things; beginning with his mother's breast and rising gradually as he grows older and knows more, until he embraces other persons and attains to trust in God.[124] We said before (p. 83) that the duties of the limbs are imperfect unless accompanied by the intention of the heart. A man's motive must be sincere. It must not be his aim to gain the favor of his fellowmen or to acquire honor and fame. The observance of the prescribed laws must be motived by the sole regard for God and his service. This we call the "unity of conduct." The meaning is that a man's act and intention must coincide in aiming at the fulfilment of God's will. In order to realize this properly one must have an adequate and sincere conception of God's unity as shown above; he must have an appreciation of God's goodness as exhibited in nature; he must submit to God's service; he must have trust in God alone as the sole author of good and evil; and correspondingly he must abstain from flattering mankind, and must be indifferent to their praise and blame; he must fear God, and have respect and awe for him. When he is in the act of fulfilling his spiritual obligations, he must not be preoccupied with the affairs of this world; and finally he must always consult his reason, and make it control his desires and inclinations.[125]