Sanctified by Grace (Eilers and Strobel) is an attempt to do theology in a way that involves more than the comprehension of Christian truth, rather it is an attempt to do theology in a way that helps bring about Christian faithfulness.
In their preface to the book Eilers and Strobel write that the normal Christian life is intimately and inescapably theological and that the work of Christian Dogmatics can and should participate in the sanctification of the Holy Spirit who forms Christians in the likeness of Christ.
Having said that they notice that there is often a divide between doctrine and theology on the one side and spirituality and ministry on the other. In this book they hope to help tear down that false dichotomy. In my own opinion the doctrine that they start with fits this theme very well. If there is a doctrine that many Christians see as useless, though true, is the doctrine of the Trinity. Thus inviting Fred Sanders to write a chapter on this topic which gives itself over so easily to this false divide is a great move.
In this chapter Sanders sets our spiritual growth in the middle of a Trinitarian truth, specifically Trinitarian adoption. He argues that believers are adopted into the life between the Father, Son, and Holy Spirit. The eternal begetting of the son stands behind the temporal mission of the Son to save humanity. The Spiration of the Spirit stands behind the Spirit’s work in uniting us to the Father and Son. Thus, the Christian life itself can only be understood in light of the Trinity.
For me the highlight of this chapter included his discussion of how eternal processions give rise to temporal missions. The relationship between these two is often tricky and convoluted. Most theologians intuitively know there is a link, but that link is hard to pin down. Sanders does a good job of explaining the connection without being dogmatic about the “link” between the two.
Another highlight was his discussion of adoption. Sanders does a fine job navigating between the view that our sonship is merely metaphorical and the opposite view that we become totally immersed in the life of God (erasing the creator/creature distinction). Rather by advocating a soteriology of Trinitarian adoption, he is able to maintain our intimacy but distinction from God.
Overall Sanders does a great job of showing how the doctrine of the Christian life is shaped by Trinitarian though, specifically the eternal processions of the Triune God. He succeeds in showing that the Christian life is filial by essence.