One rat (female mouse) had once burnt a ghee lamp which was offered by someone else on ekadasi day. By doing so, she achieved a rarely achievable human form and at last attained the topmost destination.
A person who does not offer a ghee lamp in Lord Kesava's temple in Karttika, that foolish person is not addressed as a Vaisnava.
Just as by rubbing of two sticks of wood one can see fire, so by offering a burning ghee wick to the Lord in the month of Karttika, one can see his merits without a doubt.
If even for a short time somebody burns a lamp in the temple of Lord Sri Hari, then whatever sins he has acquired for millions of kalpas (one kalpa equals 1000 yugas) are all destroyed.