The cross - or better, the crucifix - draws us to the heart of Jesus Christ.  We cannot help but look in awe and adoration at the one who is crucified for our sake.  Jesus himself said, "When I am lifted up, I will draw all people to myself" (Jn 12:32).  We adore you, O Christ, and we bless you, because by your Holy Cross you have redeemed the world.