Ekam Tamil: ஏகம் - "the supreme oneness") is the term used in Akilattirattu Ammanai, the holy book of Ayyavazhi, to represent The Ultimate Oneness. In Thiruvasakam-2 it was stated that it was from this Ekam that all objects, including the separate Godheads, Devas and asuras, of the universe formed. As per Akilam, this state of ekam is beyond the consciousness and derived to beyond the state of changing and is the extreme state in which the whole universe exists.
In Saivism, Ekam is used commonly to refer to the oneness of God, but in Ayyavazhi the basic oneness is separately symbolized to be supreme and ultimate beyond all God-heads and powers.
The Ekam is said to be the supreme as well as the ultimate self from which the whole cosmos formed. This formless attribute is said to be defined from the human point of view. But this formless Ekam, without losing its constant and formless nature, is present inside every things in the universe. That is, it remains as infinite within every finite, formless within every definite form. It is the supreme absolute self in which all the substances of cosmos shares their existence.
The derivations of Ekam in Ayyavazhi scriptures are sometime close to the pantheistic form of theology. In the mythology of Ayyavazhi God-heads such as Siva, Vishnu are said to be the godheads who have power to rule this Ekam, varying from time to time, Siva until Kaliyuga and Vishnu from the starting of Kaliyuga. There are separate quotes in Akilam for focusing Siva as well as Vishnu as capable for position. But, still the Ekam is addressed beyond these god-heads.
But when Vaikundar, is jailed in Singarathoppe, he says "I am the one who created the Ekam and the one who is omnipresent everywhere". By this, the theology reveals Vaikundar (God) as beyond the attributes of Ekam, which moves the theology of Ayyavazhi more towards pantheism.