Lord Rama's actions are intended to only begin to be grasped by human beings. This is one of the basic elements from the epic for Lord Rama is the clear embodiment of what dharma means in this life. It follows that the hope would be that we would be able to better understand just a glimpse of what pure dharma looks like. In this light, one has to understand the complexity within Lord Rama's actions. It would be with this opening that I think discussion of how Lord Rama received Devi Sita after Ravana is defeated could commence. It should be noted that Lord Rama recognized the intrinsic duty of a husband having to rescue his wife, or the bond that one spouse feels towards another. He approaches the task with this in mind. Ravana is a demon, but Lord Rama did not seek to attack him until it became evident that Ravana's lawlessness began to permeate the law driven basis of Lord Rama. Lord Rama is not an "avenging angel." Rather, he is carrying out his dharma, or duty as a spouse. It is Ravana who escalates this into a war of all wars. When Lord Rama does rescue Devi Sita, he embraces the dharma element zealously, as he views what he did without attachment, without glory, and without emotional passion. That is difficult for us to grasp. Yet, it represents how Lord Rama teaches the lesson that is intrinsic to the Hindu religion in that one must learn to do their duty without any attachment of external or sensory reality towards it.
It is here where I think that further explication is needed in regard to Lord Rama making Devi Sita go through the fire. The most banal reading of this would be that it's a husband who believes his wife to be impure and thus demands her to test her purity. I, for one, do not fully accept this because such a reading goes against the example of dharma and complex duty that Lord Rama has represented up to that point in the epic. It would seem contrary to such a nature that now, with Ravana gone, that he suddenly becomes sensory driven. I think that Lord Rama recognizes that one has a duty to purge oneself when immersed in a setting of complete sensory perception and degradation. Devi Sita witnessed Ravana at his most base and was surrounded by the exploits of sensory reality. Perhaps, an interpretation of Lord Rama asking Devi Sita to walk through the fire was a way of purging herself of the filth that she had to witness and experience, which would be why Agni, the god of fire, lifts her out to make clear her purity and virtue is intact, rising above the filth that surrounded her, akin to a lotus who blossoms out of filth. It might be here where Lord Rama's actions can begin to be discussed.