We have ordained that our Cause be taught through the power of utterance.

Some form of coercion was sometimes used in past religions to gain new followers. This is no longer permissible, as Bahá’u’lláh informs us in this passage from the Súriy-i-Haykal (Súrih of the Temple). 

Say: We have ordained that our Cause be taught through the power of utterance. Beware lest ye dispute idly with anyone. Whoso ariseth wholly for the sake of his Lord to teach His Cause, the Holy Spirit shall strengthen him and inspire him with that which will illumine the heart of the world, how much more the hearts of those who seek Him. O people of Bahá! Subdue the citadels of men’s hearts with the swords of wisdom and of utterance. They that dispute, as prompted by their desires, are indeed wrapped in a palpable veil. Say: The sword of wisdom is hotter than summer heat, and sharper than blades of steel, if ye do but understand. Draw it forth in My name and through the power of My might, and conquer then with it the cities of the hearts of them that have secluded themselves in the stronghold of their corrupt desires. Thus biddeth you the Pen of the All-Glorious, whilst seated beneath the swords of the wayward.

If ye become aware of a sin committed by another, conceal it, that God may conceal your own sin. He, verily, is the Concealer, the Lord of grace abounding. O ye rich ones on earth! If ye encounter one who is poor, treat him not disdainfully. Reflect upon that whereof ye were created. Every one of you was created of a sorry germ. It behoveth you to observe truthfulness, whereby your temples shall be adorned, your names uplifted, your stations exalted amidst men, and a mighty recompense assured for you before God.

 Bahá’u’lláh