It can easily become our preferred approach to Scripture.
Joseph Epstein (A Literary Education and Other Essays) describes departments of English in America’s universities as having been taken captive by the winds of ideological fashion, so that they have “sold out the riches of literature for a small number of crude ideas – gender, race, class, and the rest of it – and hence gave up their cultural birthright for a pot of message.”
This is what they do who practice what might be described as a hermeneutics of convenience. Theologians, preachers Bible teachers, and writers who begin the work of interpretation with some preferred opinion or view will inevitably wrest the Scriptures to support their position.
Having hoisted their sails into the spiritus mundi or the whims of fancy, they twist the plain teaching of Scripture into a mandate for their preferred agenda. In the process, they forfeit the long heritage of Christian interpretation and culture, and take the faith once for all delivered to the saints captive to mere ideology.
A hermeneutics of convenience can distort the Scriptures as well by beginning with a Biblical idea and making it the key to all Biblical understanding. Bonhoeffer, in The Cost of Discipleship (chapter 3) is very much to the point about this matter, demonstrating how we can allow an abstract principle, even the principle of grace, to keep us from complete submission and explicit obedience to the Word of Christ.
Those who approach the work of hermeneutics in this way would remake the whole history of Biblical interpretation into their own image, which, if they are allowed to succeed, would destroy interpretation of Scripture by making hermeneutics the servant of messaging, rather than the other way around.