Foundation of all evil, is lying

In creation and nature evil does not exist at all; but when the natural qualities of man are used in an unlawful way, they are blameworthy.
If a rich and generous person gives a sum of money to a poor man for his own necessities, and if the poor man spends that sum of money on unlawful things, that will be blameworthy. It is the same with all the natural qualities of man, which constitute the capital of life; if they be used and displayed in an unlawful way, they become blameworthy.
Therefore it is clear that creation is purely good.
Consider that the worst of qualities and most odious of attributes, which is the foundation of all evil, is lying. No worse or more blameworthy quality than this can be imagined to exist; it is the destroyer of all human perfections, and the cause of innumerable vices. There is no worse characteristic than this; it is the foundation of all evils.

Selected Writings of Abdu’l-Bahá P.321