What does J.S. Mill mean by "if they can once get their creed taught from authority"?

Question

What does J.S. Mill mean by "if they can once get their creed taught from authority"?

Does it mean that they receive the authority's creed and consider it their own creed, or that they manage to get their creed accepted by authority and disseminated as authoritative information?

There is a class of persons (happily not quite so numerous as formerly) who think it enough if a person assents undoubtingly to what they think true, though he has no knowledge whatever of the grounds of the opinion, and could not make a tenable defence of it against the most superficial objections. Such persons, if they can once get their creed taught from authority, naturally think that no good, and some harm, comes of its being allowed to be questioned. Where their influence prevails, they make it nearly impossible for the received opinion to be rejected wisely and considerately, though it may still be rejected rashly and ignorantly; for to shut out discussion entirely is seldom possible, and when it once gets in, beliefs not grounded on conviction are apt to give way before the slightest semblance of an argument. Waiving, however, this possibility—assuming that the true opinion abides in the mind, but abides as a prejudice, a belief independent of, and proof against, argument—this is not the way in which truth ought to be held by a rational being. This is not knowing the truth. Truth, thus held, is but one superstition the more, accidentally clinging to the words which enunciate a truth. (On Liberty, J.S. Mill)

For more context: https://www.gutenberg.org/files/34901/34901-h/34901-h.htm

Answer 1

Likely the latter : An opinion holder manages to get his creed supported by an authority and disseminated as authoritative information.

Let us now pass to the second division of the argument, and dismissing the supposition that any of the received opinions may be false, let us assume them to be true, and examine into the worth of the manner in which they are likely to be held, when their truth is not freely and openly canvassed. However unwillingly a person [opinion holder] who has a strong opinion may admit the possibility that his opinion may be false, he ought to be moved by the consideration that however true it may be, if it is not fully, frequently, and fearlessly discussed, it will be held as a dead dogma, not a living truth.

There is a class of persons [opinion giver] (happily not quite so numerous as formerly) who think it enough if a person [opinion receiver] assents undoubtingly to what they [opinion givers] think true, though he [opinion receiver] has no knowledge whatever of the grounds of the opinion, and could not make a tenable defence of it against the most superficial objections. Such persons [opinion givers], if they can once get their creed taught from authority, naturally think that no good, and some harm, comes of its being allowed to be questioned. Where their [opinion givers’] influence prevails, they make it nearly impossible for the received opinion to be rejected wisely and considerately, though it may still be rejected rashly and ignorantly; for to shut out discussion entirely is seldom possible, and when it once gets in, beliefs not grounded on conviction are apt to give way before the slightest semblance of an argument. Waiving, however, this possibility—assuming that the true opinion abides in the mind [of the opinion receiver], but abides as a prejudice, a belief independent of, and proof against, argument—this is not the way in which truth ought to be held by a rational being. This is not knowing the truth. Truth, thus held, is but one superstition the more, accidentally clinging to the words which enunciate a truth.