At the beginning of the process of creation, Lord Brahma created the ‘Four Kumaras’ or the ‘Chatursana’. As the Four Kumaras were born from the mind by just a desire (manas) of Brahma they are referred to as his Manasaputras. Their names are : Sanaka, Sanandana, Sanatana and Sanat Kumara.
Due to the boon from their father Brahma and the strength of their tapa, the Four Kumaras looked like 5 year old. Jaya and Vijaya, the gate keepers of the Vaikuntha stopped the Kumaras at the gate, thinking them to be children. They told the Kumaras that Shri Vishnu is resting and that they cannot see them now. Sanat Kumars replied Lord love His devotees and are always available to for His devotees. You are no one to stop us from seeing our dear Lord. But Jay Vijay didn't understood their point and kept on arguing for long time. Though Sanat Kumars are very pure and have no trigunas of Maya in them (Sato, Rajo, Tamo) but by the plan of Lord to teach His gate keepers a lesson, He circulated anger in pure hearts of Sanat Kumars. The enraged Kumaras cursed both the Dwara Palas, the gate keepers Jaya and Vijaya, that they would have to give up their divinity and born as mortals on Earth and live there.
In the first birth as enemy to Shri Vishnu, Jaya and Vijaya were born as Hiraneyaksha and Hiraneyakashyipu in Satya Yuga. Hiranyaksha was an asura, the son of Diti and Kashyapa rishi. He was slain by the Lord Vishnu after he (Hiranyaksha) took the Earth to the bottom of what has been described as the "Cosmic Ocean". Lord Vishnu assumed the Avatar of a boar - Varaha and dove into the ocean to lift the Earth, in the process slaying Hiranyaksha who was obstructing Him. The battle lasted one thousand years. He had an elder brother named Hiranyakashipu, who after having undertaken penances which made him incredibly powerful and invincible unless several conditions were met, was later slain by Lord Narasimha, another incarnation of Shri Vishnu.
Also read a wonderful story about Shri Krishna and sweeper of his temple: