Do you have to be a monk or a nun to become enlightened?
 
Of course not. Some of the Buddha's most accomplished disciples were lay men and women. Some were spiritually developed enough to instruct the monks. In Buddhism the level of one's understanding is the most important thing and that has nothing to do with whether one wears a yellow robe or blue jeans, or whether one lives in a monastery or a home. Some might find the monastery, with all its advantages and disadvantages to be the best environment in which to spiritually grow. Others may find the home, with all its joys and sorrows, to be the best. Everyone is different.