Alpha 1 – historicism/mythicism
For my Alpha group, here’s a debate between Zeba Crook (a non-Christian New Testament scholar) and Richard Carrier (possibly the only reasonably weighty scholar who argues complete mythicism). For our purposes, as none of us think the mythicist position is correct, the relevant portion is from about 11 minutes to about 31 minutes, which is Zeba Crook talking (No, it isn’t necessary to watch the whole hour and three quarters).
Zeba give a good overview of the position that the early Christians progressively mythicised an historical figure with a few excellent examples.