There is no keeping up faith except by prayer and watchfulness. As prayer declines in the bosom, so does the strength of faith. You may go on neglecting prayer and supplication until every grain of faith seems lost out of your bosom, and may come at last to think you never knew anything of a work of God upon your heart, and have been deceived in believing there was any grace there.
By watchfulness also is the love of God maintained. Unless you watch against your besetting sins, against the snares spread for your feet, against the temptations that daily and hourly beset your path, against being overcome by the strength or subtlety of your unwearied foe, you are sure to fall; and if you fall you will bring guilt and bondage, darkness and distress into your mind, and cut off for a time all friendly intercourse with God.
Therefore you must pray and watch; for without watchfulness, prayer is of little efficacy. And if we neglect the Scriptures, or read them carelessly, unbelievingly, they will do us little good. They must be read with believing eyes and heart, received as the revelation of God, and must be mixed with faith, or assuredly they will not profit us (Heb. 4:2).
The life of God is a very deep, secret, and sacred thing in the soul. God, it is true, will maintain it; he will not leave his work unaccomplished; but unless we read and pray, watch and meditate, wage war against besetting sins, and seek the Lord's face continually, we shall find the strength and power of faith very sensibly decline; and if so, there is no comfortable walking with God.