“But there can be equally little doubt that brief verses cannot and should not take the place of reading the Scripture as a whole. The verse for the day is still not the Holy Scripture which will remain throughout all time until the Last Day. Holy Scripture is more than a watchword. It is also more than “light for today”. It is God’s revealed Word for all men, for all times. Holy Scripture does not consist of individual passages; it is a unit and is intended to be used as such.
As a whole the Scriptures are God’s revealing Word. Only in the infiniteness of its inner relationships, in the connection of Old and New Testaments, of promise and fulfillment, sacrifice and law, law and gospel, cross and resurrection, faith and obedience, having and hoping, will the full witness to Jesus Christ the Lord be perceived. This is why common devotions will include, besides the prayer of the psalms, a longer reading from the Old and the New Testament.”
Dietrich Bonhoeffer Life Together: The Classic Exploration of Christian Community