In answer to an email question:
“How do you understand Ezekiel 18:31, in relation to monergism and synergism. I thought that the ‘God gives the new heart’ aspect of biblical teaching clearly entailed monergism, but I have no idea what to do with this verse.”
Commands serve different purposes in Scripture. One is to reveal our duties, another is to expose our needs. Indeed, the two can be interrelated.
One way of exposing my spiritual need is to confront me with a moral obligation which I, as a sinner, am unable to discharge. That makes me aware of my iniquity and need of grace. A parallel to Ezekiel is Deut 10:16 & 30:6.
As Daniel Block, in the standard commentary on Ezekiel, explains,
"This text [18:31] is unique in that it calls on the wicked to take the initiative in making their own hearts and spirits new. What is promised elsewhere as a divine act and as a gift (36:26-27) is now recast as a command. The use of the imperative mood does not mean that Ezekiel believes his audience capable of moral and spiritual self-transformation. The command 'create a new heart and a new spirit for yourselves' is a rhetorical device, highlighting the responsibility of the nation for their present crisis and pointing the way to the future. The prerequisites for positive divine intervention are a wholesale reorientation of life and an internal change in disposition. The former will not happen without the latter," The Book of Ezekiel: Chapters 1-24, 588.