Trust is hard to earn but easy to lose. Unfortunately, there is no magic bullet for how to gain trust. What we do know is that we can only move forward, and that looking back and looking only at our failings does not give a true reflection of who we really are.
That is not to say that telling the truth isn’t important – it is! Rabban Gamliel, one of the great rabbis of early Jewish history, said that the world stands on, among other things, truth. The Torah tells us to stay far away from falsehoods. Interestingly, this is the only commandment in the torah where it says “stay far away.” Obviously it is important. But, the truth is that we all make the mistake of telling a lie. And when we do make that mistake, the important thing is what happens next.
In Jewish tradition, we understand that it is part of our job in the world to make mistakes. It doesn’t matter whether they are big mistakes or little ones, every person makes them. That is why the word for sin in Hebrew comes from an archery term meaning “to miss the mark.” We acknowledge that part of being alive is making mistakes. And it is not the mistakes that matter so much as what we learn from them and how we grow after we make mistakes. That is teshuvah – making a real change.
When we lie, we hurt people around us; those we lied to and those we lied about. We also make it hard for people to believe us again in the future, as your question acknowledges. But, if we make amends by apologizing and showing that we understand that what we did was wrong, we are already half way to starting the trust-rebuilding process. Maimonides says that what comes next is the most important step. When we are put in a similar situation we have to make a better decision. If we lied about doing our homework and the next time we are asked we tell the truth, and our teacher sees that we told the truth, then s/he can start to trust us again.
There are no easy answers to this question, but I believe that if you are making an honest effort, that people will respond. Trust, although hard to earn, can be earned. Even after it is lost.