Deuteronomy 6: 13:
Fear the LORD your God, serve him only and take your oaths in his name.
Introduction
Sacredness
When someone says ‘cross my heart…….’ they are consciously, or, not, invoking that ‘sacred gesture’ as a guarantee of truthfulness.
Biblically speaking, oath taking is a very serious business.
Cross My Heart.
Fear the LORD your God, serve him only and take your oaths in his name.
You shall not misuse the name of the LORD your God, for the LORD will not hold anyone guiltless who misuses his name.
But I tell you, do not swear an oath at all: either by heaven, for it is God’s throne; or by the earth, for it is His footstool; or by Jerusalem, for it is the city of the Great King.
Above all, my brothers and sisters, do not swear - not by heaven or by earth or by anything else. All you need to say is a simple “Yes” or “No.” Otherwise you will be condemned.
And if I go and prepare a place for you, I will come back and take you to be with me that you also may be where I am.
All you need to say is simply ‘Yes’ or ‘No’; anything beyond this comes from the evil one.
When God made his promise to Abraham, since there was no one greater for him to swear by, He swore by Himself, saying, “I will surely bless you and give you many descendants.”
Spiritual Perspective: The Cross is precisely where the God of the universe made His ultimate pledge to us (humanity). The Cross is the most sacred symbol. The cross is the foundation of all trustworthiness - it is God’s own sworn oath in Flesh and Blood. So do not by saying ‘cross my heart’ trivialise a most sacred symbol.