Vertically he can raise the quality of sincerity by extending it to events of greater significance. Sincerity made perfect at the level of conscience, extended horizontally to cover all our life activities and vertically to act in important events of our life will be a sincerity of power and value. If what is of value to you inwardly is also recognised by the society as valuable in their eyes, your sincerity reaches a second peak in the mountain chain of human progress. Morality is a great thing for society. If one raises his own sincerity to fulfil the moral requirements of honesty, veracity, purity, etc., etc. it will result in another crown for the inner jewel of sincerity.
Morality is great, conscience is great, society is great.
All are good in themselves. In a spiritual endeavour, they are stepping stones, not the final crown. For the final crown, the inner Divine is the sole reference. One must be sincere to the inner Divine and try to express it in speech, emotions and acts. There is a test for sincerity and its level of attainments.