We continue to find in the approach of Noah to Abinadi the workings of order, if not express law. Rather than a summary execution, Abinadi is brought before the priests. While these verses describe what happened, we must guess as to why it happened.
First, it does not appear that there is a tremendous popular support for Abinadi as it was the people who turned him over to the king. Nevertheless, it is unlikely that the ways of God were forgotten entirely, and there were likely to be some sympathizers, even if they were not as vocal as the rest of the community that had adopted the new ways. As we have developed the story of Noah and Abinadi, the theme has been a conflict between religious systems (remembering the close connection between religion and community politics at this time). It is therefore very understandable that Abinadi be brought before the priests.
Abinadi poses a religious challenge, one that should be met by the religious establishment. The intent of the priests is to "cross him," or to show Abinadi to be wrong. The presumption is that they will be able to prevail, and use their superior knowledge and position to declare victory over Abinadi's ideas. This would effectively discredit Abinadi with those who might have sympathized, and consolidate the rule of the new order over all of the people. The tactic backfires, however, as Abinadi "did withstand them in all their questions, and did confound them in all their words." This tells us that there is a religious debate being held, and that while the attempt is being made to discredit Abinadi, he is holding his own.
Textual: This interpretation of Abinadi's defense before the priests of Noah is again Mormon's summary. It is entirely possible that the perception of Abinadi's withstanding the questioning is related to Mormon's sympathy with Abinadi. As will be clear as the story continues, the priests of Noah will eventually have a very different reaction to Abinadi, and consider him to have condemned himself (though it will by they who condemn themselves in the eyes of God).