Although it may be associated with a particular religion, this symbol is the bare synonym for faith and perseverance. Present for more millennia (and millennia to come) it has instilled faith and ultimate belief among people of various cultures and traditions.
Carrying a Cross with you at all times is the way to stay assured that the force of good karma and continuous protection is next to you. After all, belief is not just hoping things will get better, it is a mindset to be learned and maintained. That gets easier with a Cross symbol to look at.