Insecurity comes form our life experiences. Often times it dates back to childhood and what learnt from what was going on in the home or from how we were treated. Many parents say things to kids that becomes a part of them as they grow up.
As we become wiser, we have to ensure that we instill in our children a high sense of self esteem so that they can become who they were meant to be. At the same time, we must work to free ourselves of our own insecurities, even if it means getting help in doing so.