In this first installment of "This One Thing I Know," Amy Grigg sits down with husband Donnie Grigg, as they trace the last few years of their life together. They talk of how they met, their family, leaving their church home in Texas to start Vertical Community Church in Fayetteville, Arkansas, the life and passing of their son Titus due to cancer, and their life journey and experiences with God along the way. They go through the ups and downs of those years, and conclude with the "one thing they know." This is their story in God's greater story.