The Seeta parityaga (Disowning of Seeta), Seeta Agnipravesha, arrival of all GODs and Sri Rama accepting Seeta episodes were described in the Sargas 115 to 118 of Yuddha Kanda of Srimad Ramayana.
The above episodes in Ramayana were inserted consciously, at a later date, by some scholars. They are interpolated stories to make believe that Sri Rama was an incarnation of Vishnu.
Sri Rama sends Vibhishana to bring Seetha to his presence. Vibhishana brings Seetha to Sri Rama's presence.
Sri Rama informs Seetha that the dishonour meted out to him and the wrong done to her by Ravana have been wiped off, by his victory over the enemy with the assistance of Sri Hanuma, Sugreeva and Vibhishana.
However, regarding with suspicion on the character of Seetha, Sri Rama disowns her and asks her to seek shelter elsewhere.
Seetha gives a taunting reply to Sri Rama, saying that why she was not abandoned by the latter, even at the time when Sri Hanuma came to see her in Lanka.
Then, Seetha requests Lakshmana to prepare a pile of fire for her to enter. When Lakshmana prepares a pyre, Seetha prays the fire-god and enters into it, in order to prove her conjugal fidelity.
Lord Brahma, Lord Shiva and other gods reach that place and eulogise Sri Rama as the incarnation of Lord Vishnu and Seeta as Lakshmi.
भवान्नारायणो देवः श्रीमांश्चक्रायुधः प्रभुः ||
एकशृङ्गो वराहस्त्वं भूतभव्यसपत्नजित् | (Yuddha Kanda 117 Sarga 13 Sloka)
"You are the Lord Narayana himself the glorious god, who wields the discus. You are the Divine Boar with a single tusk, the conqueror of your past and future enemies."
सीता लक्ष्मीर्भवान् विष्णुर्देवः कृष्णः प्रजापतिः ||
वधार्थं रावणस्येह प्रविष्टो मानुषीं तनुम् | (Yuddha Kanda 117 Sarga 28 Sloka)
"Seetha is no other than Goddess Lakshmi (the divine consort of Lord Vishnu), while you are Lord Vishnu. You are having a shining dark-blue hue. You are the Lord of created beings. For the destruction of Ravana, you entered a human body here, on this earth."
1) As Putrakamesthi episode was inserted to make believe the readers that Sri Rama was in fact the incarnation of Lord Vishnu, Seeta parityaga (Disowning of Seeta), Seeta Agnipravesha, episodes were inserted consciously to prove similar theory.
2) Hence, eulogising Sri Rama as the incarnation of Lord Vishnu and Seeta as Lakshmi by Lord Brahma and Lord Shiva WAS DONE to elevate the status of Lord Vishnu and did not fit into Srimad Ramayana
3) Beore reaching Lanka, Sri Rama always expressed his great eagerness in getting back his dear wife Seeta at the earliest. At no point of time, till his meeting with Seeta after the death of Ravana, he was depicted expressing his desire to give up Seeta as she was residing in Ravana’s house.
4) If Sri Rama already had a doubt of Seeta’s conjugal fidelity or he already decided to disown Seeta after killing of Ravana, he would have felt relieved with the news of death of Seeta. Instead, his immediate reaction to the news of Indrajit chopping off the head of illusionary Seeta was to faint away.
5) Here the question is whether Sri Rama could have behaved in that manner and disowned his dear Seeta? I firmly believe that Sri Rama's high standard of thinking will not allow him to do in such a way
6) The insertion of above episodes in Yuddha Kanda might have made the readers believe that Sri Rama was the incarnation of Lord Vishnu, who is Lokadhipati. However, this insertion had done more harm to the character of Sri Rama.
7) It gave an opportunity to Feminists, followers of other religions, atheists, etc, to criticize the exemplary character of Sri Rama, who according to these insertions, was turned into a Male chauvinist.
8) It is nothing but character assassination and in the process of elevating the status of Vishnu to that of Supreme Lord, Sri Rama had become a victim of this slander.