Ali Bin Abu Talib (may Allah be pleased with him) said: “Narrate to people what they can understand; do you want Allah and His Messenger to be disbelieved?” (Al-Bukhari)
Ibn Hajr said in Fath Al-Bari, “(In this narration) there is evidence that ambiguous knowledge should not be mentioned amongst the general public.”Sheikh Muhammad Bin Saleh Al-Uthaymeen (may Allah have mercy on him) explained this very important and often misunderstood point beautifully. After mentioning the narration of Ali, he states:
“It is therefore an aspect of wisdom in Da’wah that you should not surprise people with things they are not able to comprehend. Rather, you should call them in stages, bit by bit until their minds settle.
“(The statement of Ali) ‘Do you want Allah and His Messenger to be disbelieved in?’ is a rhetorical question, posed as criticism of such behavior. It means: By narrating to people what they cannot understand, do you want Allah and His Messenger to be disbelieved in ? This is because in such cases when you say, ‘Allah said, and His Messenger said,’ people will say, ‘You have lied,’ if their minds cannot comprehend what you are saying. Here, they are not disbelieving in Allah and His Messenger, but they are disbelieving you because of what you have attributed to Allah and His Messenger. Thus they will end up disbelieving in Allah and His Messenger – not directly – but through the person who transmits this knowledge (i.e. you).
“So, should we stop telling people things they cannot understand even if they need to know? The answer is: No, we do not leave this knowledge altogether. But we should tell them in a way that they are able to understand it. This is done by telling them in stages, bit by bit until they can accept the thing we want them to know and they can feel comfortable with it. We do not abandon knowledge that people cannot understand and just say ‘this is something they will reject or dislike so we will not speak about it.’“The same is the case with acting upon a Sunnah that people are not used to and which they might find objectionable. We should act by this Sunnah only after informing people about it, such that they will be able to accept it and feel comfortable about it.
“We learn from this narration that it is important to employ wisdom in calling to Allah, and that it is incumbent upon anyone who calls to Allah to consider the level of understanding of those he is inviting, and that he should put everyone in their proper place.” (Majmu’ Fatawa Bin Uthaymeen, vol. 10, p. 140)