Those who long for success in their actions worship the gods here, for in the human world, success born of action comes quickly.
Explanation
Krishna is explaining to Arjuna why people turn to different deities: they want results from their actions (karma), and such results come quickly in the human world. This follows the previous verse, where he says he responds to people in the way they approach him. Some commentators read this as a gentle contrast with the higher goal of liberation, while others read it simply as a statement that such worship does bear fruit.