Spiritual complacency or lukewarmness is a spiritual malady which consists in a sort of spiritual languor that saps the energies of the will, inspires one with a horror for effort and thus leads to the decline of the Christian life. It is a kind of sluggishness, a species of torpor which, though not death as yet, insensibly leads to it through a gradual weakening of one's moral forces. One may compare this to a physical disease which, little by little preys upon some vital organ.

The causes of spiritual complacency are essentially two in number: lack of spiritual nourishment and/or the entry into the soul of some noxious (spiritual) germ. In order to live and to grow one's soul needs wholesome spiritual nourishment. Now the soul is nourished by the sacraments as well as by the various spiritual exercises, i.e., meditation, devout spiritual reading, prayer, examination of conscience, fulfillment of the duties of one's state in life etc. All of these things have for their primary purpose to keep the soul in union with Almighty God. Therefore if these exercises are performed with negligence, with voluntary distractions or without efforts to react against spiritual sluggishness (or not performed at all) the soul is then deprived of many graces, is poorly nourished and becomes weak and incapable of practicing the virtues in face even of little difficulties. The outcome of this is spiritual apathy or the gradual weakening of the soul -- a form of spiritual anemia which paves the way for the entrance of some destructive germ.

The dangers of this state of tepidity consists in the gradual weakening of the soul's energies -- a condition fraught with severe spiritual dangers. This is the sense in which Our Lord speaks to those who are lukewarm: "I know thy works, that thou art neither cold nor hot. I would that thou were cold or hot. But because thou art neither cold nor hot, I will begin to vomit thee from My mouth." (Apoc III:15)

The first effect of lukewarmness is a kind of blinding of the conscience. One excuses one's faults and thus one's judgement becomes warped and thus sins, in and of themselves grave, are considered slight. Thus one develops a lax conscience. Along with this comes a gradual weakening of the will.

In order to save one's soul must then take the remedies to counteract spiritual lukewarmness. Firstly, one must frequent the sacraments; one must have frequent and fervent recourse to the sacrament of penance and frequent and fervent reception of the Our Lord in the Blessed Sacrament. Secondly, one must seek diligently to fulfill the duties of one's state in life. In addition, one must fervently practice exercises of piety such as prayerful devotions (such as those held each Friday evening at 7:30 p.m. but most especially on the First Friday of each month) and Benediction of the Most Blessed Sacrament.