Sahasranamam has 1000 names of a God, but why is it necessary.
What is the prominence of it?
One of the primary tasks in the Path of Bhakthi, is to extol the glory of the Lord in myriad ways. Some read his life history. Some sing songs such as Bhajans. Yet others chant hymns.
In verse 10.9 of the Gita, Lord Krishna says :
The thoughts of My pure devotees dwell in Me, their lives are surrendered to Me, and they derive great satisfaction and bliss enlightening one another and conversing about Me.
God is considered beyond attributes and beyond the reach of the mind and the word. The phrase 'Aprapya Manasashaha' refers to this transcendental nature. However, in the Path of Bhakthi, the Lord is also the supreme master and is considered to be the embodiment of all virtuous qualities, kalyana-gunas.
By focussing the mind on the Lord's attributes described in the thousand names, there is a chance for the devotee's mind to be focussed continuously on the Lord.
For instance, the significance of chanting Vishnu Sahasranama is explained here :
Every one of the one thousand names is full of significance and refers to one particular guna (quality, characteristic, or attribute) of Paramatma. These names invoke a sense of bonding with the Lord. The meanings of the names give us an understanding and depth of God as there is a deep connection between the name and the named.
The necessity of cleansing our body regularly to maintain hygiene and good health is recognized by everyone. But with the busy nature of today’s world, we do not see our mind the same way as we see our body. As a consequence, the need for keeping our minds clean is not appreciated...Prayers are a means to mental cleansing when they are chanted with sincerity and devotion.
Similar are the benefits of chanting the Sahasranama of any deity, such as Lalita Sahasranama and so on.
Is it necessary ? : No. It is one of the many ways on the Path of Devotion. Each devotee may choose his technique appropriate for his inclination and ability.
The chanting of these are among some of the most commonly found practices in many Hindu household families. It has been present for ages and has continued by tradition. They do have a calming effect on the mind.
It is also one of the recommended practices by Adi Shankara in his Bhaja Govindam, considered a a beginner-treatise for many aspirants of Vedanta. This verse covers a synthesis of Bhakthi, Satsang and Charity.
Sing the Gita. Utter the thousand names of the Lord. Meditate continuously on Sripati. Spend your time in the company of the good. Give away your wealth to the weak and the needy people.