Past behaviour is one of the best predictors of future behaviour. We are all creatures of habit who tend to do the same things over and over again. So, if you want to know whether you can trust someone it is best to look at the pattern that they have already established in that area of their lives.
When a person promises to pay the bills on time but has been delinquent in the past - be cautious! It isn't very wise to believe someone with a huge pile of speeding tickets who claims "This will never happen again". A child who has failing grades should be suspect about their statements that from then on they will study every single night.
Imagine that trust is like a wire hanger. It can be bent slightly but, if it ever breaks, it is almost impossible to put together again. That is the way that it is with trust. You can be somewhat flexible with it but, once trust is broken, other people tend to lose faith that you will be trustworthy in the future.
I remember hearing an individual a few years ago talk about how his wife didn't know how to forgive. He had an affair and then thought that because he was "caught" that she should just forgive him, believe his promises and move on. She indicated that she didn't know if she could trust him again and the truth came out that this wasn't the first affair that he had during their relationship. The man was so quick to try to blame her for not forgiving instead of recognizing that he was responsible for a pattern that threatened the marriage and left everyone hurt.
You see, it is easy to make promises but promises don't guarantee positive change.
Mary Poppins called them "piecrust promises - easily made and easily broken". Just because someone seems sincere in their commitment does not mean that you have to believe change will occur. And you certainly don't have to take any blame for losing trust in the person who has repeated a dysfunctional pattern.
So many people ask me whether they should believe the promises that they have been given and how they will know that the person who gave them will follow through and honour their words.
Well, there is only one way that you will truly know if the person has changed for the good and that is to watch him/her over time to see if their behaviours and words line up.
And we're not talking short-term. It usually takes a person a fair amount of time to get into trouble and therefore will likely take a fair amount of time to prove that s/he has truly changed.
Bankruptcy requires seven years before a record is wiped clean. A failing student will need at least a year of regularly doing homework and studying to see a significant improvement in grades.
So, if your partner has been abusive or was cheating on you, why would you immediately forgive and believe that s/he will change without carefully watching their behaviours and choices for at least eighteen months?
The next time that someone repeatedly makes irresponsible choices and then asks "Don't you trust me?" the best answer you can give is "NO"