A heart is often used to represent emotional love, which involves feelings of deep affection, care, and emotional attachment towards another person. The crucifix also represents love - sacrificial love, doing what is best for others to the point where we are willing to lay down our lives. Jesus' sacrificial love is unconditional; He gives us His love even when we don't deserve it. Put your crucifix at home in a prominent place (or get one, if you don't have one already) so that, every time you look at it, your heart is filled with zeal for the sacrificial love God bestows on us, which we are in turn expected to share with others.