'behind the age'?

"These are held up as superstitious who claim a hearing for God when, on other days than Sabbath, He calls men away from the vanities of the world to consider things unseen and eternal. Those who attempt to fence the table of the Lord are represented as mystical and straight-laced and, because conservative of what is scriptural, they are said to be 'behind the age'. . . . To be behind an age that is drifting away from truth and ungodliness is the only safe, the only dutiful, position." (John Kennedy, The Present Cast and Tendency of Religious Thought and Feeling in Scotland,