Complex sentence: In the 90's, the Assemblies of God created a new national evangelistic program called "The Decade of Harvest", which during this period, was the First Congress of church growth with Pastor David Yongui Cho.
Split into simpler sentences: In the 90's, the Assemblies of God created a new national evangelistic program called "The Decade of Harvest". Which, during this period, was the First Congress of church growth with Pastor David Yongui Cho.