Real faith changes everything. It works "through love" (Gal. 5:6). In other words, real faith acts. That is because saving faith is more than mental assent to truth. It is the "assurance of things hoped for, the conviction of things not seen" (Heb. 11:1). It is an "assurance" seated in the heart. An earnest "conviction" that these things are true.
If you are "assured" that you will someday stand before the judgment seat of Christ, and if you are "convicted" that God is infinitely holy, you will flee to the gospel for refuge. If you feel a deep "conviction" that Christ is your happiness, in both this life and the next, you will pursue him aggresively. If you are assured that Christ judges idolatry then you will "flee from idolatry" (1 Cor 10:14). If someone walks into a theatre and yells "fire," those with "assurance" and "conviction" head for the exit. Those who lack these qualities will mock and scoff.
Our churches are filled with well-meaning people who only have the faith of demons (James 1:19). They believe, but their faith lacks "assurance" and "conviction." Its domicile is the mind. It has not descended the thirteen short inches to the heart. How can one tell? Their faith does not express itself with works.
Which are you today?