You aim at a devout life, dear child, because as a Christian you know that such devotion is most acceptable to God’s Divine Majesty.

But seeing that the small errors people are wont to commit in the beginning of any undertaking are apt to wax greater as they advance, and to become irreparable at last, it is most important that you should thoroughly understand wherein lies the grace of true devotion — and that because, while there undoubtedly is such a true devotion, there are also many spurious and idle semblances thereof; and unless you know which is real, you may mistake, and waste your energy in pursuing an empty, profitless shadow. Arelius was wont to paint all his pictures with the features and expression of the women he loved, and even so we all color devotion according to our own likings and dispositions. One man sets great value on fasting, and believes himself to be leading a very devout life, so long as he fasts rigorously, although the while his heart is full of bitterness — and while he will not moisten his lips with wine, perhaps not even with water, in his great abstinence, he does not scruple to steep them in his neighbor’s blood, through slander and detraction. Another man reckons himself as devout because he repeats many prayers daily, although at the same time he does not refrain from all manner of angry, irritating, conceited or insulting speeches among his family and neighbors. This man freely opens his purse in almsgiving, but closes his heart to all gentle and forgiving feelings toward those who are opposed to him; while that one is ready enough to forgive his enemies, but will never pay his rightful debts save under pressure. Meanwhile all these people are conventionally called religious, but nevertheless they are in no true sense really devout. When Saul’s servants sought to take David, Michal induced them to suppose that the lifeless figure lying in his bed, and covered with his garments, was the man they sought; and in like manner many people dress up an exterior with the visible acts expressive of earnest devotion, and the world supposes them to be really devout and spiritual-minded, while all the time they are mere lay figures, mere phantasms of devotion. 

But, in fact, all true and living devotion presupposes the love of God — and indeed it is neither more nor less than a very real love of God, though not always of the same kind; for that Love . . . shining on the soul we call grace, which makes us acceptable to His Divine Majesty — when it strengthens us to do well, it is called Charity — but when it attains its fullest perfection, in which it not only leads us to do well, but to act carefully, diligently and promptly, then it is called Devotion. The ostrich never flies — the hen rises with difficulty, and achieves but a brief and rare flight, but the eagle, the dove, and the swallow, are continually on the wing, and soar high — even so sinners do not rise toward God, for all their movements are earthly and earthbound. Well-meaning people, who have not as yet attained a true devotion, attempt a manner of flight by means of their good actions, but rarely, slowly and heavily; while really devout men rise up to God frequently. In short, devotion is simply a spiritual activity and liveliness by means of which Divine Love works in us, and causes us to work briskly and lovingly; and just as charity leads us to a general practice of all God’s commandments, so devotion leads us to practice them readily and diligently. And therefore we cannot call him who neglects to observe all God’s commandments either good or devout, because in order to be good, a man must be filled with love, and to be devout, he must further be very ready and apt to perform the deeds of love. TCA  

St. Francis de Sales (1567-1622) was bishop of Geneva and one of the Church’s greatest spiritual writers through treatises such as “Introduction to a Devout Life” (excerpted here). Canonized in 1665 and proclaimed a Doctor of the Church in 1877, he is patron of Catholic writers and the Catholic press. His feast day is Jan. 24.