Speaking of those Bibledex videos: if I ever get the chance to preach in the same place for 66 consecutive weeks, I'd love to do a series of sermons like this – one on every book of the Bible. It would be an exciting, demanding discipline to have to identify one theme for each biblical book – not only its internal theme, but also its location and function in the wider canon – and to proclaim the subject-matter of that book in one simple address. (I'm talking here about a sermon, which by definition can have only one point, one Word – not a lecture, which might have various different points and themes and observations.)
There's a lot to be said for the use of a lectionary cycle. But the lectionary tends to presuppose, rather than to foster, a broad understanding of the biblical story. Lectionaries were designed for use in societies that were already implicitly Christian – societies in which the rhythms of the liturgical year, and the broad sweep of the biblical narrative, could be more or less taken for granted. In the Revised Common Lectionary (which my own church follows), just look at the theological subtlety with which the OT and NT readings are often connected: a subtlety that is quite lost on anybody without a good working knowledge of scripture and liturgical tradition. And preachers only exacerbate the problem when they take these subtle liturgico-theological connections as the theme of their proclamation, instead of preaching from the texts themselves. (Preachers, please note: the content of your proclamation is not the liturgical calendar, but the Word of God!)
For many congregations today, it would be better to interrupt the lectionary cycle so that specific books of the Bible could be expounded in depth. I once attended a church where the minister interrupted the lectionary for some months in order to preach all the way through the Epistle to the Romans. It was a transformative experience. And alongside depth, our congregations need biblical breadth. Imagine preaching for a whole month on the broad theme of "the Prophets": from that time on, all those weird lectionary readings from Isaiah, Jeremiah, and Jonah would actually start to make sense. (If the lectionary is a sort of doxological hermeneutic, don't forget that the shaping, selection, and arrangement of texts into a scriptural canon is already its own liturgical hermeneutic: with this difference, that the canonical hermeneutic is confessed to be divinely given, so that all subsequent interpretive frameworks are answerable to this "inspired" framework. So the way the Book of Jonah functions in the lectionary is derivative of its function as part of the canonical collection of "the Prophets".)
If you're a congregational minister today, I reckon one of your tasks is to cultivate the sort of catechised community in which the lectionary cycle can be used with profit – in other words, to foster enough biblical literacy for the congregation to be able to participate meaningfully in the church's tradition of doxological reading.
That's why I'd love to spend 66 weeks preaching on every book of the Bible: not instead of the lectionary, but for the sake of the lectionary's proper and fruitful use.