Only Jesus, first published in English in 1962, is the last of Luis M. Martínez's writings, and widely hailed as his magnum opus. Combining robust doctrine and authentic mysticism, Martínez leads his readers through a quadripartite meditation on the person of Jesus Christ. In Part One, he considers the unfolding of revelation through the Incarnation, public ministry, suffering, death, and resurrection of Jesus. Parts Two and Three reflect on the union between Jesus and the Christian faithful, which both springs from and resides in the depths of the Sacred Heart. To conclude the volume, Martínez contemplates the "Divine Repose" and the indwelling of God in those who love him.

As noted in the Translator's Preface, Martínez has deservedly received favorable comparisons to spiritual masters such as the Dominican Henri Lacordaire and the Benedictine Dom Columba Marmion. Like the works of his confréres, Martínez's Only Jesus is marked with a penchant for plumbing the depths of the Divine mysteries and an unquenchable thirst for the salvation of souls.