It is necessary for us to avoid alike all the passions which corrupt the soul, but most especially those, which from themselves generate numerous sins. I mean such as the love of money. It is in truth of itself a dreadful malady, but it becomes much more grievous, because it is the root and mother of all mischiefs. Such also is vainglory. See, for instance, how these men were broken off from the faith through their love of honor. "Many," it saith, "of the chief rulers also believed on Him, but because of the Jews they did not confess Him, lest they should be put out of the synagogue." As He said also to them before, "How can ye believe which receive honor one of another, and seek not the honor that cometh from God only?" (c. v. 44.) So then they were not rulers, but slaves in the utmost slavery. However, this fear was afterwards done away, for nowhere during the time of the Apostles do we find them possessed by this feeling, since in their time both rulers and priests believed. The grace of the Spirit having come, made them all firmer than adamant.
Source: Homily on the Gospel of John 69