A conversation is worthwhile when it is gracious. It's in the Bible, Colossians 4:6, NIV. "Let your conversation be always full of grace, seasoned with salt, so that you may know how to answer everyone."
Active listening makes a worthwhile conversation. It's in the Bible, James 1:19, NIV. "My dear brothers, take note of this: Everyone should be quick to listen, slow to speak and slow to become angry."