Everyone is endowed with a hridaya (spiritual heart). When you fill your heart with love and compassion, peace will reign supreme in the world. There will be no jealousy, hatred or anger, but only love everywhere. Restlessness will disappear from the face of the earth. One who has filled his heart with compassion will always remain in peace. It is most essential to know this truth. People mistake hridaya for the physical heart but truly it represents the all-pervasive Atmic principle, in other words, the Aham. So you should keep your heart absolutely pure and sacred.

 -Vidya Vahini, Chap 16.

A pure heart is the essence of all spiritual practices. - Baba