The Bible says, "Out of the abundance of the heart, the mouth speaketh." This explains why a person in love is so inspired that he becomes poetic when talking about love. Jim Bishop must have been in high heavens and in the throes of love when he said, "True love is night jasmine, a diamond in darkness, the heartbeat no cardiologist has ever heard. It is the most common of miracles, fashioned of fleecy clouds - a handful of stars tossed into the night sky."
It is also said that one can give without loving but cannot love without giving. Hence, lovers express their love by giving gifts to each other. On special occasions like engagement and wedding days, those who can afford will give, for example, a diamond heart jewelry as a sign of their true love.
Expressing one's love is, however, more than just giving and receiving of material things. It needs to be expressed verbally and through actions. Both must always go together, to give love it's true meaning.