The cross has different meanings to people depending on their religious persuasion. I grew up in a Protestant church where I learned that our cross was empty, unlike the crucifix in the Catholic Church, because Jesus had risen from the dead and the cross symbolizes the risen Christ.
Once, a Mormon friend, told me that the cross is not displayed in the Church of Latter Day Saints, because an instrument of torture and should not be revered. I kind of feel the same way when "The Old Rugged Cross" is sung in church. How can I sing about loving the old rugged cross when it was was used to kill Jesus and MANY other people in a sadistic, horrible manner?
Sometimes I wear a silver necklace with a Celtic cross on it. The four arms of the Celtic cross are thought to be representative of the four directions of the compass, the four elements of Fire, Earth, Air and Water, and as representation of our mind, soul, body and heart. The center ring of the Celtic Cross is said to be evocative of the Celtic symbol for infinite love.
The cross was an important symbol in many pre-Christian religions and cultures. The swastika was a type of cross historically used as a symbol in Buddhism, Jainism and Hinduism. It was widely popular in the early 20th century as a symbol of good luck or prosperity. Unfortunately this symbol was adopted as a symbol of Nazism in the 1920s and 30s so it has become a symbol of fascism.
When I see a cross I think about the metaphysical symbolism: that the horizontal bar represents our earthly life, and the vertical bar represents our connection with heaven. Heaven and Earth meet at the center of the cross which represents the inner sanctum - the still, quiet place within where we connect with the Divine Mystery.
When my husband went on a mission trip to Ethiopia he brought back a pair of Ethiopian cross earrings for me. Ethiopian crosses are made of elaborate latticework - each one uniquely fashioned. The intertwined latticework represents everlasting life. I like this meaning, too. And yes, I believe that Jesus died on a cross and returned to prove to us that life is everlasting.