Most of us will admit that we are NOT perfect.
From time to time we say and do things that are not loving, kind, or helpful. In a marriage these failures build into walls of separation. If you would like to remove past failures, you must first identify them.
Get pen and paper and then, ask God to bring to your mind, the ways you have hurt your spouse in the past. Now, go to your children individually and ask them to tell you times when they have seen you being unkind to your spouse. Get ready, because children can be brutally honest. Then ask the same question to close friends who have had opportunity to observe your behavior. This process can be painful, but it is the first step in dealing with past failures.