Someone recently asked us the reason for truth being in the title when much of the book is about building intimacy. Truth is the beginning of intimacy, rather trust is the beginning and has its beginnings in truth.
We've all had those people in our lives who were so brutally honest that we avoided them like the plague unless we needed to get an honest opinion. We might not always like what they say, but those people can be trusted because they are honest, even to their own hurt. While marital truth need not be harsh or brutal, it does need a certain die-hard, sold out to the cause of honesty effect.
Marriage is not a temporary thing. It's permanent. How can two people who'll be together the rest of their lives live peacefully with all kinds of secrets and hidden agendas? It can't. From the beginning until the end of your marriage, truth should be an integral part of everything else.