One of the most important elements to successful communicating as a missionary is an unconventional one: love. Still, this should not come as a shock, for when asked what is the greatest commandment (and therefore the most essential thing we can be doing as people and as missionaries), the Lord answered his apostles:
Jesus said unto him, Thou shalt love the Lord thy God with all thy heart, and with all thy soul, and with all thy mind.
This is the first and great commandment.
And the second is like unto it. Though shalt love thy neighbour as thyself.