Psalms 91:11
Above all else, guard your heart,
for it is the wellspring of life. Prov. 4:23
guard the heart... because it is a temple, a sacred dwelling place.
Watchfulness guards the heart
. Ten maidens watched and according to a story that jesus told. Five of them, because of the special character of their watching, recognized the Bridegroom when he arrived. They were invited to the festivities.
"When He appears, we will see Him as he is becuase we will be like Him." 1John 3:2
And David said, His angels are ordered to guard and surround us completely.