That interpretation only works if you desperately want the comment containing the phrase "the church" to be wrong. If you insist on this unusual interpretation, then yes, farming isn't at least five times older than the church. But if you go with the usual interpretation of "the church" as a metonym for Christianity, as was very clearly intended by the implications of the statement, it is correct.
Why not go talk to some Muslims about the Islamic church? Or some Hindus about the church of Shiva? I'm sure you'll find the discussion edifying!
