Devotional service (DS)equals Krishna. Devotional service is so powerful that it can even cause Krishna to change his will. For example he broke his promise not to wield weapons in the battle of Kuruksetra, because he wanted to keep Bhisma’s vow intact and to protect Arjuna. In Srimad Bhagavatam 1.9.37 Bhismadev says: Fulfilling my desire and sacrificing His own promise, He got down from the chariot, took up its wheel, and ran towards me hurriedly, just as a lion goes to kill an elephant. He even dropped His outer garment on the way.