Hazrat Ghulam Ahmad, the Promised Messiah & Mahdias, the Founder of the Ahmadiyya Muslim Jamaat says:
We should only worship that Almighty God, who rewards even for a little work.
A story goes that once three men were trapped in a mountain. They had taken refuge in a cave when a rock fell in front of the cave, blocking the exit.
Upon this, they said, ‘Now only our virtuous deeds will rescue us’.
One of them said, ‘Once I hired a few workmen. One of them left before the payment was made. I searched for him, but he could not be found. I bought a goat from his wages that multiplied into a herd in a few years’ time. One day that person appeared and said that he had worked for me and that it will be my kindness to pay for his labour. I handed over the whole herd to him. O Allah! If You liked my virtuous act, then ease my difficulty for me’. The rock elevated slightly.
The second person then narrated his story and said, ‘O Allah! Ease my difficulty if You liked my virtuous act’. The rock elevated a little more.
The third person described his story, ‘My mother was old. One night she asked for a glass of water. By the time I brought the water, she was already asleep. I did not wake her fearing that she would be uncomfortable. I stood the whole night with the glass of water. I gave her the water when she woke up in the morning. O Allah! Remove my difficulty if You liked my virtuous act’.
The rock then moved enough to let them escape. The Almighty Allah rewarded all of them for their virtuous deeds. (Malfużat, V. 6, p. 26–27, Urdu, edition 1984)