Valmiki is explicit about the purpose of Rama avatar. “Rama upholds the Kshatriya dharma conferred by His birth; yet as the Supreme Lord He also upholds the Saranagati dharma, and promises to protect those who seek refuge in Him; He is the sole protector of every created being in the universe and He is the very embodiment of dharma.” This makes Him compassionate to a fault when dealing with erring jivatmas in general and with Ravana in particular pointed out Srimati Jaya Srinivasan in a discourse.
Ravana had wronged Him in a personal way by abducting Sita. Yet Rama gives Ravana many chances to rectify his sin and hand over Sita and be saved from destruction and death. He sends his message of compassion through Hanuman and Angada. He is willing to pardon all other atrocities if only he repents. Could there be any match to such Rama’s benevolence in the battlefield when Ravana stands weaponless before Him?
What a struggle it had been for Him along with Lakshmana and the vanara heroes to fight against the magic tricks of warfare practised by the rakshasas? Here was a chance to finish him off and put an end to all the evil he stood for. Yet Rama gives him a chance to retire and resume the fight with renewed strength the next day. Rama is capable of eliminating Ravana by His mere Sankalpa. So too is Sita’s power. But the divine couple undergoes the stress and strain of human birth to show the world that the law of dharma cannot be transgressed. To the Lord, true victory is in the inner transformation of the human soul when there is repentance for one’s sinful tendencies and a genuine desire to reform. The promise of redemption for even the worst of sinners is topmost in the Lord’s agenda.