"Keep thy heart with all diligence, for out of it are the issues of life." - Proverbs 4:11-13 (Audio)
The following sermons are on Proverbs 4:23:
The Spiritual Watch, by Thomas Watson
Keeping the Heart, by Rev. Stephen Hamilton
An Appointment for a Heart Check Up, by Rev. Ian Goligher
A Lost Spiritual Discipline, by Pastor Kevin Boling
A True Healthy Heart Program, by Rev. David VanBrugge