。
Meeting her has brought spiritual richness to his life.
Literal
Her [with-との] encounter [subject-が] his life [to-に] spiritually moisture [object-を] bringing.
出会い ('encounter, meeting') is the key noun. 精神的に ('spiritually, mentally') is the adverb. 潤い (うるおい, 'moisture, enrichment') is used metaphorically — literally 'moisture' but figuratively 'emotional richness, warmth.' もたらしている ('is bringing about') uses the progressive to indicate an ongoing effect. The water metaphor for emotional nourishment is characteristically Japanese.