[More important than all is] a diligent endeavor to have the power of the truths professed and contended for abiding upon our hearts, that we may not contend for notions, but that we have a practical acquaintance within our own souls. When the heart is cast indeed into the mould of the doctrine that the mind embracethâ€”when the evidence and necessity of the truth abides in usâ€”when not the sense of the words only is in our heads, but the sense of the thing abides in our heartsâ€”when we have communion with God in the doctrine we contend forâ€”then shall we be garrisoned by the grace of God against all the assaults of men.
Quoted by John Piper in The Future of Justification from John Owen, Vindiciae Evangelicae; or, The Mystery of the Gospel Vindicated and Socinianism
Examined, Vol. 12, The Works of John Owen, ed. William Goold (Edinburgh: Banner of Truth,