Question from a devotee: There was a Ram temple in our house; I was in the habit of hearing the Tulsi Ramayan, and meditating on the form of Lord Ram. But after marriage, in my in-laws' house, I began reading the Durga Saptaśhati and observing Navrātras. When I heard the Bhāgavat saptāha, I liked the leelas of Shree Krishna. How should I decide which God to worship?
Answer by Swamiji: Although Ram, Durga, Krishna are all different forms of the one Supreme Lord, yet it is advisable to focus your devotion on a single form. There is a Hindi saying:
eka sādhe saba sadhe, saba sādhe saba jāya
With the same logic, if you try to love all the forms of God, you will end up loving none. But if you devote your mind to one form, you will develop love for all of them. So you must choose one form to worship, which is called "Iṣhṭa Dev", or the devotee's chosen form of God for devotion.
Now the question you have asked is about how to choose your Iṣhṭa Dev. In deciding this, you must consider which form of God is attractive to the mind. If your Iṣhṭa Dev has a beautiful form, you will find it much easier to meditate on Him. Also, if your Iṣhṭa Dev has wonderful pastimes, it will be very helpful in your devotion. To turn your mind towards God, leelas also play an important role. By hearing and chanting those leelas, devotees increase their love for God. From both these view points, devotion to Shree Ram and Shree Krishna is both sweet and easy. Hence, They are also the most popular Iṣhṭa Devs in India. Their sweet pastimes are lovingly sung and remembered in temples and houses in every part of the country.
Amongst Them, Shree Krishna manifests four special nectars, above and beyond any other Avatar of God:
1. Exceptionally attractive form (His famous three-fold bending form with a flute on His lips).
2. Amazing sweetness of His flute that attracts even Lord Shankar.
3. The sweetest childhood pastimes that enchant the minds of devotees.
4. Leelas displaying the greatness of love, which reveal how God forgets His Almightiness because of the love of His devotees.
For all these reasons, I would highly recommend that you make Shree Krishna and His Divine Consort, Shree Radha Rani, as your Iṣhṭa Dev. However, if you decide to choose any other forms of God, that is also fine.