"The root of a plant or tree makes no show above ground. If you dig down to it and exaime it, it is a poor, dirty, coarse-looking thing, and not nearly so beautiful to the eye as the fruit or leaf or flower. But that depised root, nevertheless, is the true source of all the life, health, vigour and fertility which your eyes see, without it the plant or tree would soon die."-John Charles Ryle (1816-1900)

J.C. Ryle here is telling us that we need to have private devotions with our Lord, and not simply go to a "Church" that has all the popularity of the day.

This is the root of which He speaks. Jesus is the root isn't He; through the Holy Spirit.

Jeremiah says: "Blessed is the man that trusts in [ public & private] the Lord, and whose hope is the Lord.
For he shall be as a tree planted by the water, and that spreads out her roots by the river, ...her leaf shall be green; ....neither shall she cease from bearing fruit!" (17:7-8)