The withholding of truth is a sin, but the revelation of the truth requires pre conditions. Many truths that are revealed prematurely, and without the right foundations can lead to aggravation of corruption.
Sugar, is sweet. But the very same sugar if placed, as it is, in to the mouth of a child, would cause suffocation. We don’t need to explain what sugar is and how the body needs it to work properly, rather the sugar should be dissolved in water and slowly given to the child.
Many truths require the preliminary introductions to be explained first, as many people are not prepared to accept the truth that is stated once and in its pure form. People go willingly inside a shower and wet their heads and hair, but if unready, a single glass of water poured on them will result in an unpleasant reaction.
A testimony to this is the fact that people are prepared to go and kiss the hands of the Jurists and pay their Khums and Zakat to them, but are not so enthusiastic about paying their taxes… because of their understanding of the Ayahs in the Qur’an and narrations about such issues, and after hearing it from those they trust, and from their faith and cultural point of view, they are willing to make those payments. Likewise, with the visitations to the Imams and Imam Zadas, because they are aware of their significance they are prepared to go through hardship just to visit them and pay their respects and would be proud of having visited them, yet someone who is not aware of who they are would find no motivation to even send a greeting to them from afar.
So having intellectual premise and foundations for belief is a prerequisite.