Some believe that the Bible prohibits using the symbol of the heart, since it is often associated with the pagan observance of Valentine's Day.
We should remember that God created the heart, and the Bible refers to it many times. Its writers use this organ as a symbol of our attitude and thoughts, for example (see Genesis 6:5; Exodus 35:5; Psalm 14:1; Isaiah 6:10; Matthew 11:29; Hebrews 4:12; etc.).
The pagans merely adopted a stylized drawing of a heart as a symbol in their worship, as for Valentine's Day. In fact, a number of other objects in God's creation have been treated in a similar manner. However, the misuse of an object by this or that group, even if the people are atheistic or heathen, should not prohibit a Christian from putting it to a proper use. Based on this principle, it is not wrong to use the heart shape in jewelry, pillows, cookies, or other items. Any religious usage of this symbol, of course, would fall under the prohibitions of the second commandment (Exodus 20:4-6).
Another factor to consider is conscience. If a person feels that the heart symbol is "tainted" because of its connection with Valentine's Day, then it would be wise to avoid its use. The Bible tells us that "whatever is not from faith is sin" (Romans 14:23).