I love the broader implications of this ayah. 
For some of us Islam is something inherited. Questions about the religion are not welcomed.  By that I mean deep intellectual ones, questions which are important to have a root deep conviction in one God. We just follow what our parents 'told' us. Often times asking questions in such scenarios can get us in trouble.
This ayah is a gem! It encourages us to ask and makes us feel comfortable if we don't know. The thing is not knowing is OK but not knowing and not seeking is the problem.