Lock and Key Golden Antique a symbol of love and belong. 128 x 128 clear background. Since the earliest times, great steps have been taken to secure personal property, be it material, familial, or spiritual. To protect a treasure chest filled with gold or a heart just as pure, humans have found ways to keep looters at bay. Locks and keys speak of the value of what is locked away, and imply 'restricted access'. Neither was heaven accessible without the prescribed 'keys to the kingdom', of which Christ made Peter the guardian.