Complex sentence: Shortly after his marriage, Baker joined the Disciples of Christ church and engaged in part-time preaching, primarily for the opportunity it gave him to engage in public oratory, an activity that eventually made him famous.
Split into simpler sentences: Shortly after his marriage, Baker joined the Disciples of Christ church and engaged in part-time preaching. The primary attraction of his ministry seemed to be the opportunity it gave him to engage in public oratory, an activity that eventually made him famous.