From the great J. I. Packer as quoted on Justin Taylor’s blog:
[We can] correct woolliness of view as to what Christian commitment involves, by stressing the need for constant meditation on the four gospels, over and above the rest of our Bible reading: for gospel study enables us both to keep our Lord in clear view and to hold before our minds the relational frame of discipleship to him.
The doctrines on which our discipleship rests are clearest in the epistles, but the nature of discipleship itself is most vividly portrayed in the gospels.
Some Christians seem to prefer the epistles as if this were a mark of growing up spiritually; but really this attitude is a very bad sign, suggesting that we are more interested in theological notions than in fellowship with the Lord Jesus in person.
We should think, rather, of the theology of the epistles as preparing us to understand better the disciple relationship with Christ that is set forth in the gospels, and we should never let ourselves forget that the four gospels are, as has often and rightly been said, the most wonderful books on earth.
—J. I. Packer, Keep in Step with the Spirit: Finding Fullness in Our Walk with God (Grand Rapids, MI: Baker, 2005), p. 70, 71.