One becomes Narayana by His Nāma japa - Vishnu Sahasra Nama in Padmapurana

[V Subrahmanian]

पद्मपुराणम्/खण्डः ६ (उत्तरखण्डः)/अध्यायः ०७१

https://sa.wikisource.org/s/xpp

रामो रामश्च कृष्णश्च बुद्धः कल्की ततः स्मृतः ।
एते दशावताराश्च पृथिव्यां परिकीर्तिताः २७।
एतेषां नाममात्रेण ब्रह्महा शुध्यते सदा ।
प्रातः पठन्जपन्ध्यायन्विष्णोर्नाम यथा तथा २८।
मुच्यते नात्र संदेहः स वै नारायणो भवेत् ।

Verse 27: Matsya, Kurma, Varaha, Narasimha, Vamana, Parashurama, Rama, Rama (Balarama), Krishna, Buddha, and Kalki are remembered as the ten avatars, celebrated across the earth.

Verse 28–29: By merely uttering their names, even one who has committed the gravest sin (brahmahatya) is always purified. One who recites, chants, or meditates upon the names of Vishnu each morning shall be liberated and verily become one with Narayana—of this there is no doubt.

This chapter lists 1,000 names of Vishnu, which Shiva gave to Parvati. It's very interesting to read the names, which take us through the various Avatara-s too.    

Om

subbu