Evangelicalism is characterized by an awareness of the personal character of knowing God and an experience of the actual presence of another Someone in intimate contact over the course of a shared history. The evangelistic shorthand for this has to do with inviting Jesus to take up residence in your heart as your personal Savior or with the theme of friendship with God. "Person" is a key term in Trinitarian theology, and it is no accident that the personal emphasis of evangelicalism coheres well with this element of Trinitarianism. This pervasive personalism also gives a particular tone to evangelical prayer, one which emphasizes a freedom of speech and a direct, even informal manner of talking to God.

From Wesley's hymns to contemporary choruses, affective worship experience is a recurring mark of evangelical church life. This emotional depth, while not adequate to support theological reflection on its own, provides a rich and engaging context for Trinitarian theology. Above all, it provides the kind of incentive and communal sanction necessary to encourage anybody to undertake the kind of challenging thinking required to bring Trinitarian theology into sharper focus. This stirring up of the depths of the heart and mind is crucial to the Polanyian strategy: "Since tacit knowing depends on where your attention is focussed, it won't work without caring. . . . There is no discovery without a desire to know and a belief that there is something to know."48 Emotionally engaging worship is a communal effusion of that caring without which the attention will not be focused and without which there will be no confidence that there is something worth expending cognitive energy toward investigating. Communal praise of God is itself already a focusing of the mental apparatus of attentiveness in the right direction.

One of the most important resources evangelicalism has for developing the tacit dimension of Trinitarianism is its distinctive posture toward Scripture. Evangelicals are a variety of biblicists (if the term has not grown too pejorative), and they believe that the Scriptures are the medium of God's personal address to them; the Bible is God's word. Accordingly, evangelicals have developed a host of spiritual disciplines focused on the Word of God that provide perfect examples of the Polanyian motif of indwelling a subject in order to understand it better.49

I believe that the above resources show enough promise for developing a rich fund of tacit Trinitarianism that it is fair to assert that evangelicalism has within its own particular genius all that it takes to be more robustly Trinitarian. If I am right about resources like these as sources for Trinitarian understanding, then the evangelical malady is 

Chart 1.1: Tacit Trinitarianism of Evangelical Practices

The Evangelical Practice ------Its Tacitly Trinitarian Dimension
Getting saved-----Being adopted as sons by encountering the gospel Trinity
Knowing Jesus personally----- The Spirit joining believers to the life of Jesus
Devotional Bible reading- ----Hearing the Father's word in the Spirit
Conversational prayer-----The logic of mediation; prayer in the name of Jesus

actually more mysterious than ever because we have everything necessary for health and yet we remain ill. It would be good if evangelical theology would lay hold of its tacit resources for Trinitarian theology and fulfill its potential. At this point, even a bit of amicable competitive spirit would be beneficial on all sides: if a nonliturgical, nontraditional, and nonsacramental family of Christians would undertake to prove itself more solidly and productively Trinitarian than its liturgical, traditional, and sacramental cousins, both parties would benefit from the competition, to the benefit of the ecumenical church. Everybody could be a winner in the "more Trinitarian than thou" fight that might break out if evangelicals rise to their potential and develop the genius of their own movement in the direction of reinvigorating Trinitarianism as a force in Christian life and thought.

This chapter has necessarily been more abstract and methodological than the others in this book. I hope it has also been more suggestive of future possibilities in the broad field of evangelical Trinitarianism. In the following chapters we will not be following up every one of those possibilities. Instead, we will focus on the main things: the gospel and its application to individuals, Bible study, prayer, and the church as a community on a mission.

[This excerpt was taken from The Deep Things of God, 2010, by Fred Sanders, published by Crossway Books. Used by permission.]