I am having spiritual practice for the last three years. I do not find any improvement. Why?

There is improvement. Your mental images are strong and steady now. Remember that
there is no barometer or thermometer to read your spiritual progress in the spiritual realm. You
are now giving only half of your mind to God. Collect the dissipated rays and give the full mind
to God. I assure you, “You will realize Him this very moment”.

From „May I answer that“ by Swami Sivananda (1987-1963). More Informations… http://bit.ly/axpSuC