John Schmalzbauer has an interesting post at Faith and Leadership on the way that mainline Protestant denominations have relied on para-church and evangelical resources for Christian education rather than cultivating materials of their own. Here is his conclusion:
To be sure, mainline denominations have benefited from the assistance of evangelical para-church ministries (including Sunday School publishers). As Presbyterian Richard Hutcheson notes in “Mainline Churches and the Evangelicals,” the role of the para-church is to work alongside or beside the wider ecclesia.
And yet if congregations do not learn to tend their own theological gardens, they will not survive. Such a development would be a loss to both mainline denominations and to the larger church.