The Promised Messiah (as) & Imam Mahdi (Guided One), Hazrat Mirza Ghulam Ahmad (as)
All actions are directed by one’s belief. For example, if someone were to mistake arsenic for bamboo, they would consume many grams of it. However, if the individual was certain that the substance before them was a deadly poison, they would not bring it anywhere near their mouth. In order to embody true virtue, a belief in the existence of God is necessary, for human authorities are not privy to what a person does in their own home or the actions they commit in hiding. Although a person may claim by tongue to be righteous, if they hold contrary beliefs in their heart, they have no fear of being called to account for it by the people. For there is no government on earth whose fear inspires man constantly and equally during the night and day, in darkness and in light, in seclusion and in public, in private and in the open, at home and in the marketplace. Therefore, in order to reform our morals, belief in such a Being is necessary who watches over man in all states and at all times, and who is privy to all the deeds, actions, and secrets of man’s heart. For in actuality, only such a person is truly righteous whose outer and inner state are one, and whose heart accords with his image. Such a person walks on earth like an angel. An atheist is not subject to an authority that can move him to attain the best of morals. All outcomes are the result of belief. For example, a person who recognises a snake’s burrow will not put their finger in it. When we know that a certain amount of strychnine is deadly, we firmly hold that it has the power to kill, and it is due to this very belief that we will not consume it so that we may be saved from death.
Hazrat Mirza Ghulam Ahmad (as), Malfuzat-Volume 2 (Tilford, Surrey: Islam International Publications Ltd., 2019), 32-33.