Keep Your Heart With All Vigilance

We must maintain a holy jealousy of ourselves, and set a strict guard, accordingly, upon all the avenues of the soul; keep our hearts from doing hurt and getting hurt, from being defiled by sin and disturbed by trouble; keep them as our jewel, as our vineyard; keep a conscience void of offence; keep out bad thoughts; keep up good thoughts; keep the affections upon right objects and in due bounds.

Matthew Henry