The Wildwood Crest spouter is wrong about the number of millennials and their lack of interest in going to church. Pew Research Center Factank, April 25, 2016: There are 75.4 million millennials ages 18-34. That number will peak 81.3 million in 2036. Pew has found that the older generations of Americans are not passing along the Christian faith as effectively as their forebears.