Shiv Puran says that Lord Hanuman was the incarnation of Lord Shiva. Lord Ram was the incarnation of Lord Vishnu. It is said that Lord Hanuman took birth just to help Lord Ram, in his aim of establishing Dharma on the earth.
Scriptures mention that there were a few things only Lord Hanuman could do. Take a look at what those six things were.
Crossed The Massive Sea
Lord Hanuman, Angad, Jamvant etc. came to the sea, while on their search for Goddess Sita. As they saw the extreme size of the sea, they were left spellbound. None of them could gather the courage to cross such a big sea. Upon this, Jamvant, a member from his army, recalled that Hanuman was the only one who was blessed with such wonderful strength. He made Hanuman understand his capabilities, after which Lord Hanuman is believed to have crossed the sea in one go.
Found Goddess Sita
Lord Hanuman was on his search for Goddess Sita. As he reached Lanka, the kingdom of Ravana, he met the demoness Lankini at the gates of the kingdom. The demoness was so powerful that no one other than Lord Hanuman could have defeated her. He used his mental and physical strength rightly, and thus successfully found out Goddess Sita sitting under the tree in the Ashoka Vatika. The incarnation of Goddess Lakshmi, Goddess Sita also took no time to recognise him. None other than Lord Hanuman could have reached her at that time.
Killed Akshay Kumar
After conveying the message of Lord Ram to Goddess Sita, Lord Hanuman destroyed most of the parts of Lanka. When Ravana sent his son Akshay Kumar to him, Lord Hanuman killed him as well. This brought tensions in the entire kingdom. Ravana called Hanuman to his court and still failed in making him his captive. Hanuman finally put the whole Lanka on fire. He did so, just to make him realize the prowess of the enemy, Lord Ram. Only Hanuman could do it that efficiently.
Trusted Vibhishan & Took Him To Lord Ram
When Lord Hanuman heard somebody chanting the name of Lord Ram, he took the form of a priest and appeared before him. As Hanuman asked, he came to know that the man was, Vibhishan, the brother of Ravana but a supporter of Lord Ram. When Vibhishan expressed the desire to meet Lord Ram, no one but Lord Hanuman showed trust in him and thus, took him to meet Lord Ram. Vibhishan later helped Lord Ram in killing Ravana.
Carried The Sanjeevani Booti
Indrajeet, the son of Ravana, had used Brahmastra during the battle between Lord Ram's and Ravana's army. Majority of the army, as well as Lord Ram and Lakshman, had fainted because of its effects. Sanjeevani Booti was the only remedy for it. And none other than Hanuman could get it from the Himalayas in time. Lord Hanuman, carried the whole mountain on his arms.
Killed Many Other Demons & Defeated Ravana Once
Lord Hanuman killed many demons during the battle. This includes demons such as Dhumraksh, Ankpan, Devantak, Trishira, Nikukbh etc. It is said that a fierce battle between Lord Hanuman and Ravana had also taken place. Ravana was defeated and the entire army of Hanuman rejoiced when he defeated him once. But Ravana could not die at the hands of Lord Hanuman since Ravana was destined to be killed by Lord Ram.