Islam and the Bahá’í Faith
"But, O my brother, when a true seeker determineth to take the step of search in the path leading to the knowledge of the Ancient of Days, he must, before all else, cleanse and purify his heart, which is the seat of the revelation of the inner mysteries of God, from the obscuring dust of all acquired knowledge, and the allusions of the embodiments of satanic fancy. He must purge his breast, which is the sanctuary of the abiding love of the Beloved, of every defilement, and sanctify his soul from all that pertaineth to water and clay, from all shadowy and ephemeral attachments.
He must so cleanse his heart that no remnant of either love or hate may linger therein, lest that love blindly incline him to error, or that hate repel him away from the truth. Even as thou dost witness in this day how most of the people, because of such love and hate, are bereft of the immortal Face, have strayed far from the Embodiments of the divine mysteries, and, shepherdless, are roaming through the wilderness of oblivion and error.
That seeker must at all times put his trust in God, must renounce the peoples of the earth, detach himself from the world of dust, and cleave unto Him Who is the Lord of Lords. He must never seek to exalt himself above any one, must wash away from the tablet of his heart every trace of pride and vainglory, must cling unto patience and resignation, observe silence, and refrain from idle talk. ..." - Book of Certitude by Baha'u'llah, p.192
The following verses need no comment or introduction:
"O ye who believe! If a wicked person comes to you with any news, ascertain the truth, lest ye harm people unwittingly, and afterwards become full of repentance for what ye have done." - [Qur'an 49:6]
"A believer, a man from among the people of Pharaoh, who had concealed his faith, said: "Will ye slay a man because he says, 'My Lord is Allah'?- when he has indeed come to you with Clear (Signs) from your Lord? and if he be a liar, on him is (the sin of) his lie: but, if he is telling the Truth, then will fall on you something of the (calamity) of which he warns you: Truly Allah guides not one who transgresses and lies!" - [Qur'an 40:28]
"and say not to any one who offers you a salutation: 'Thou art none of a believer!'" - [Qur'an 4:94]