In verse 31, Moroni described actions that were pollutions. In this verse, the actors are themselves pollutions. Not only what they do, but who they are (or who they have become) qualifies as religious pollution. By presenting the actor as well as the actions, Moroni can emphasize the contrast between motivations—God’s glory or the world’s praise,—which was emphasized in the Sermon on the Mount and at the Temple:
Therefore when thou doest thine alms, do not sound a trumpet before thee, as the hypocrites do in the synagogues and in the streets, that they may have glory of men. Verily I say unto you, They have their reward.
But when thou doest alms, let not thy left hand know what thy right hand doeth:
That thine alms may be in secret: and thy Father which seeth in secret himself shall reward thee openly.
And when thou prayest, thou shalt not be as the hypocrites are: for they love to pray standing in the synagogues and in the corners of the streets, that they may be seen of men. Verily I say unto you, They have their reward. (Matt. 6:2–5, see also 3 Ne. 12:2–5)
Those who engage in religious practices “because of the praise of the world… have their reward.” But it is a reward from the earth, and they thus forfeit a heavenly reward.