The smile of the contemplative in the presence of the Beloved is merely a physical expression of the total joy one perceives as one communes with God. St. Bernard used to say, "The joy of being in love is in the very loving." In other words, joy is not to be sought for itself, but is a by-product of love, and the smile is but the physical, exterior expression of the inner joy-love.
Silence is the language spoken by solitude. There is something awesome and breathtaking about real silence; it is numinous, pulling us out of self-containment and calling us toward the invisible. Spiritual seekers "home in" on silence as homing pigeons to their roost, because therein lies the language for personal communication with the sacred. Silence accompanies us into our innermost selves where we are present to the sacred. When word breaks into that kind of silence, there is communion.