6289 Faith is a matter of personal conviction, and does not depend on worldly motives. Worship should depend on pure and sincere Faith, but often does not: for motives of worldly gain, ancestral custom, social conventions or imitative instincts, or a lethargic instinct to shrink from enquiring into the real significance of solemn acts and the motives behind them, reduce a great deal of the world's worship to sin, selfishness, or futility. Symbolic idols may themselves be merely instruments for safeguarding the privileges of a selfish priestly class, or the ambitions, greed, or lust of private individuals. Hence the insistence of Islam and its Teacher on the pure worship of the One True God. The Prophet firmly resisted all appeals to worldly motives, and stood firm to his Message of eternal Unity.