This is an interpretation and a bad translation being used.
They wrote..."For the Sadducees say that there is no resurrection, nor an angel,
nor a spirit; but the Pharisees acknowledge them all."
Its not "a" spirit but simply "spirit".
"With reference to their religious beliefs,
Acts 23:8 states: “Sadducees say there is neither resurrection nor angel nor spirit, but the Pharisees publicly declare them all.” It was in connection with the resurrection and brother-in-law marriage that a group of Sadducees attempted to stump Christ Jesus. But he silenced them. By referring to the writings of Moses, which the Sadducees professed to accept, Jesus disproved their contention that there is no resurrection. (
Mt 22:23-34; Mr 12:18-27; Lu 20:27-40) Later, the apostle Paul, when before the Sanhedrin, divided that highest Jewish court by playing the Pharisees against the Sadducees. This was possible because of the religious differences existing between them.—
Ac 23:6-10.
Although religiously divided, Sadducees joined Pharisees in trying to tempt Jesus by asking him for a sign (
Mt 16:1), and both groups were united in their opposition to him. Biblical evidence indicates that the Sadducees took a leading part in seeking Jesus’ death. Sadducees were members of the Sanhedrin, which court plotted against Jesus and, later, condemned him to death. Included in the court were Caiaphas, the Sadducee and high priest, and evidently also other prominent priests. (
Mt 26:59-66; Joh 11:47-53; Ac 5:17, 21) Therefore, whenever the Christian Greek Scriptures speak of certain action as being taken by the chief priests, Sadducees were evidently involved. (
Mt 21:45, 46; 26:3, 4, 62-64; 28:11, 12; Joh 7:32) Sadducees appear to have taken the lead in trying to stop the spread of Christianity after Jesus’ death and resurrection.—
Ac 4:1-23; 5:17-42; 9:14."
Sadducees — Watchtower ONLINE LIBRARY