When we are not successful, it means that our meditation is not up to standard. It is not perfect as we have not experienced peace and do not have enough patience or diligence. If these qualities have not been fully attained, we will not gain freedom. Nevertheless we can still accumulate the Perfections for our future lives.
The merit of our past lives gave us Rebirth as human beings in a Buddhist land, the land of the Dhamma. As people are different from one another, some are more careful than others, and some have more mindfulness and wisdom.
All of us, however, possess a certain amount of merit and Perfections, no matter what kind of merit it may be. It depends on the amount of meditation which we have done. If we have not “entered the stream”, but are only half way, we are still accumulating merit. We have to persevere to complete our accumulations in order to be enlightened.