Luke 1:17 (NIV)
. . . turn the hearts of the parents to their children and the disobedient to the wisdom of the righteous—to make ready a people prepared for the Lord.
How to prepare is the question. Spurgeon offered this answer back in 1887:
“. . . to get men to come to Jesus just as they are, is not an easy thing. To get them to give up the idea of preparing, to get them prepared to come without preparing, to get them ready to come just as they are, this is the hardest part of our work.“