From the text, we get the idea that Arun is trustful, compassionate, perceptive, as well as philosophical about life. He is the type of man who doesn't let life worry him, and he takes each day as it comes.
Although Arun appears to be a poor man, he still consents to take Deepak in. As for our protagonist, Deepak isn't his real name (he has alternately called himself Ranbir, Sudhir, Trilok, or Surinder). When Deepak pesters Arun to let him work for him, Arun reluctantly agrees. He can't pay Deepak but promises to feed him if he will cook for both of them.
Deepak maintains that he can definitely cook. In reality, however, he's a terrible cook, and Arun has to give the first meal Deepak makes to the neighbor's cat. In the end, Deepak's charm wins Arun over, and Arun decides to keep Deepak on as a sort of errand-boy. In exchange, Arun teaches Deepak how to write, to cook, and to add money on paper; he welcomes Deepak into his home wholeheartedly and unreservedly.
As time progresses, however, Deepak begins to feel the tug of his old life as a thief. One night, he steals a wad of cash from Arun as the older man sleeps. With the money, Deepak decides that he will go to Amritsar. However, when the time comes to get on the train, he begins to harbor reservations about his actions. Deepak feels guilty because he knows that he has stolen from an impoverished man who trusts him.
In the end, Deepak returns to Arun, and even though Arun knows what Deepak did, he chooses to keep silent about it. So, from the story, Arun is presented as a trustful, compassionate, perceptive, and forgiving individual.