Dr. George O. Wood, general superintendent of the Assemblies of God, which claims over 66 million Pentecostals worldwide, acknowledged in a letter addressing Pastor John MacArthur's Strange Fire conference that "there have been isolated aberrations of behavior and doctrine over the past century among those who self-identify as Pentecostal or charismatic." Wood insisted, however, that "the movement as a whole has proved a vital force in world evangelization."