How much does a theologist earn?

This is a bit like asking how much a doctor or a plumber earns. Obviously, the answer can vary greatly depending on the particulars of the theologian's employment. Often, they develop secondary income streams from channels such as speaking, preaching, authoring or editing journals or books, conducting seminars or counseling.

To be considered a professional theologian almost invariably indicates that one holds an advanced degree, usually a PhD, ThD (doctor of theology), DD (Doctor of Divinity), or less often, a DMin (doctor of ministry), or a DRE (doctor of religious education). Probably the bare-bones minimum degree would be an MDiv (masters of divinity), which, though still a Master's is yet a very advanced degree, its holder often having earned Master's degrees in both Old and New Testaments prior to earning the MDiv. MDiv. is the minimum degree required by the armed services to serve as a chaplain, and is often the minimum degree required to teach in a college, work as a hospital chaplain, and in some denominations, to be ordained as a minister. It takes about three years solid of post-graduate work and probably an internship and/or thesis as well.

That being said, a theologian will generally make about as much as a college professor in the same geographical region. Solo church pastors and preachers generally make about $55,000 a year, while a "senior pastor" makes about $70,000. Executive pastors who oversee a large ministerial staff make about 80,000 to 85,000.

Again, these figures are averages and there might be significant variance depending on the particulars,