Floyd Parker, «The Terms "Angel" and "Spirit" in Acts 23,8», Vol. 84 (2003) 344-365
In any discussion of the Sadducees, there will always remain a certain amount of doubt due to the paucity of sources about them. Based on what data has survived, the older theory that the Sadducees rejected the extravagant beliefs about angels and spirits provides the most convincing solution to the problem of Acts 23,8. The Sadducees’ reasons for rejecting these views were twofold: 1) angels were integrated into the apocalyptic world view that they rejected; and 2) angels often served as God’s servants to administer predestination or providence. Thus, when Paul claimed that a heavenly being had appeared to him in a manner and with a message that appeared to be predestinarian in nature, the Sadducees were unwilling to entertain the idea that an angel or spirit had appeared to him. Certainly new theories will arise in an attempt to grapple with this issue, but to re-appropriate the words of Jesus in Luke 5,39, "the old is good enough".
the proponents of the resurrection body theory have the burden of addressing the following issues: First, if the Pharisees allowed for the possibility that the risen Jesus appeared to Paul, as one must if he consistently applies the definitions inherent in this theory to Acts 23,9, how can this be reconciled with belief in a future resurrection? Obviously the appearance of Jesus to Paul was not an eschatological event since it transpired approximately two and a half decades prior to the trial recorded in Acts 23. It is inconceivable that the Pharisees would have drawn the conclusion that Jesus had been raised from the dead in any form (angel or spirit), for the resurrection was yet future (Acts 24,15). In their mind, Jesus would have to wait to be raised with the rest of humanity. They certainly would not have thought his resurrection took place at the moment of his death. Second, if the Pharisees endorsed the possibility of Jesus’ own resurrection, does this not put them in the position of conceding that the resurrection had already begun and, consequently, that Jesus was "first to rise from the dead" (Acts 26,23)? It is doubtful that the Pharisees would have allowed that the resurrection had begun before the end of the age. This, of course, is what the early Christians believed (Acts 26,23; 1 Cor 15,20.23), but one can hardly expect the Pharisees to have given ground to them by conceding Jesus’ resurrection as an angel or spirit merely to score points against their Sadducean opponents.
The final problem with the resurrection theory has to do with the nomenclature it employs to describe afterlife. The most unusual aspect of this theory may be its unconventional definition of "resurrection". Viviano and Taylor assume this term is interchangeable with various forms of afterlife, even the survival of the "spirit" or soul "apart from the body"46. In one passage, they suggest that resurrection should "be understood here in a broad sense as ‘life after death’ and certainly does not have to be taken as implying the resuscitation or reconstitution of corpses. What is asserted is rather the hope of personal victory over death, which in the first century was expressed in a variety of ways"47. In similar fashion, Lachs thinks that variety of the resurrection may have been "more Hellenistically oriented, as pure spirit"48.