Adam Clarke on Acts 26:8

That God should raise the dead? - As Agrippa believed in the true God, and knew that one of his attributes was omnipotence, he could not believe that the resurrection of the dead was an impossible thing; and to this belief of his the apostle appeals; and the more especially, because the Sadducees denied the doctrine of the resurrection, though they professed to believe in the same God. Two attributes of God stood pledged to produce this resurrection: his truth, on which his promise was founded; and his power, by which the thing could be easily affected, as that power is unlimited.

Some of the best critics think this verse should be read thus: What! should it be thought a thing incredible with you, if God should raise the dead?