John Calvin, Institutes of the Christian Religion:
Words fail to explain how necessary prayer is, and in how many ways the exercise of prayer is profitable. Surely with good reason the Heavenly Father affirms that the only stronghold of safety is in calling upon his name (Joel 2:32). By so doing we invoke the presence of both his providence, through which he watches over and guards our affairs, and of his power, through which he sustains us, weak as we are and well-nigh overcome, and of his goodness, through which he receives us, miserably burdened with sins, unto grace; and, in short, it is by prayer that we call him to reveal himself as wholly present to us. Hence comes an extraordinary peace and repose to our consciences. For having disclosed to the Lord the necessity that was pressing upon us, we even rest fully in the thought that none of our ills is hid from him who, we are convinced, has both the will and the power to take the best care of us.
Words of Grace 
Personal sanctification and prayer are linked. Prayer is one of many God given means to godliness! Gods people should be known as praying people.