The quote is from John Piper’s sermon, If You Abide In My Word, You Are Truly My Disciples.
“… if you want to know Jesus, you know him through his word. One of the most important convictions you can ever form is the conviction that Jesus, as a real, living, precious person, is known today chiefly through his word. And the only reason I say “chiefly,” and not “only,” is that in the fellowship of obedience and suffering from day to day, our personal knowledge of Jesus of goes deeper and deeper, but always through his word. But if you want to see the face of Jesus (2 Corinthians 4:6) most clearly, most surely, you must look at him through his word.”