How to decide which God to worship?

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

"If you focus all your attention on a single activity, you will succeed in it.  But if you try to succeed in multifarious things at the same time, you will fail in all of them." 

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.  

What is virtue and what is sin?

Question asked by a devotee: We have heard many times that if we do punya we go to heaven and if we do paap we go to hell. So, what are those paap and punya?

Answer by Swamiji: Our scriptures have formulated code of conduct according to class and stage of life called "Varnashram Dharm". This code of conduct have an extensive set of rules like always speak truth, never lie, give respect to your parents etc. You can get detail information about it from scriptures like Manu Smriti, Mimamsha, Mahabharat, etc. There are millions of rules. If you are to keep your feet on ground, chant this mantra, chant this one while bathing etc. But the main purpose of all these rules and regulations are to make you work in accordance to the scriptures. If you work in accordance to scripture it will be called punya (virtue) and if you go against, it will be called paap (sin).

But there is one more theory that is the theory of Karm Yog. What are you supposed to do in Karm Yog? Not much. Do whatever is required in your present situation. If you are in family, look after it. If you are a husband, earn. If you are a wife, take care of house. Perform these basic duties. But, while performing these duties, detach your mind from these worldly objects and transfer your attachment to God. Lord Krishna said in Geeta:

manmanā bhava madbhakto madyājī maṁ namaskuru |
māmevaiṣhyasi satyaṁ te pratijāne priyosi me ||

Give your mind to Me, be devoted to Me, worship Me and bow to Me. Doing so, you will come to Me alone, I truly promise you; for, you are exceptionally dear to Me.

Jagadguru Shree Kripaluji Maharaj has written in his Bhakti Shatak:

man hari meṁ tan jagat meṁ, karmayog tehi jān |
tan hari meṁ man jagat meṁ, yah mahān ajñān ||

Karm Yog is when your mind is fully observed in Shree Krishna while performing duties from your body. But, opposite of this, performing devotional formalities with body and attaching mind on world is greatest ignorance.

So this is called Karm Yog - keep your mind in God and body in the world. Rest are actions  in accordance to the code of conduct set by scriptures is virtue and going against them is sin.