Trust means a firm belief in the reliability, truth, ability or strength of someone or something. We all have varying levels of trust in ourselves, in other people, in the 'natural order', and in the divine. These are beliefs based on faith and experience that have developed over time. Sometimes our trust response is automatic and semiconscious based on history rather than on the present situation. Significant wounding in the arena of trust can lead to a "trust disorder" that might manifest as either trusting too much or being overly suspicious without regard to circumstances, both of which can lead to grievous and repetitive patterns in relationships. Perhaps the most difficult wounds to heal are those that seem to indicate "I don't care about your welfare or well being", thus parental neglect or abuse and marital affairs are examples that sorely break down to our ability to trust in others and in ourselves.
Mistrust inhibits both human and spiritual intimacy by blocking us from revealing our true thoughts and feelings. Perhaps we don't trust that another person will be able to handle what we tell them. Or maybe, as Clarissa Pinkola Estes wrote, we are on some level afraid that we won't be able to handle their reactions. Often the avoidance of conflict is so strong that we sabotage our own desire for intimacy ('into me see"). She believes that one of the reasons we are here on earth is to learn how to successfully deal with betrayal, which of course involves navigating conflict resolution and being able to withstand the anxiety of close proximity to someone who sees things differently than you.
We build trust with people who consistently demonstrate they are worthy of our trust. The ones who tell the truth, who follow through on what they say (or renegotiate with us when it the agreement proves unmanageable), inspire confidence and a sense of security. Even when trust is broken it is possible to rebuild. This is an ongoing process that requires patience over a sometimes lengthy period of time; trust cannot can be given back on demand. For us to rebuild our trust, it is helpful to understand how we react to the loss of trust. If we tend to withdraw, attack, or blame ourselves perhaps we can find less painful options of how to respond to a situation rather than just react to it. If it is difficult to manage emotional overwhelm, techniques such as EFT, EMDR, TAT can be effective in neutralizing the intensity of reaction.
One of my teachers used to say that trust is more like a basket than a blanket. It is something that you put things into, something that it is user specific, rather than something that covers overall. For example, the person you would trust with your finances might not be the person you would trust to get you to the airport on time. What a person can or cannot do is not the measure of the whole person. Being able to accurately assess the specific reliabilities of ourselves and others leads to more harmonious relationships. We can choose to accept us and them for who we are and make decisions about what to change rather than live with fear based reactivity. Staying present in the moment and making mindful choices rather than living in the past allows us to use our judgement to assess what is safe to put in that basket in front of us. The more success we experience in these determinations, the more confident we become in trusting our judgement in the here and now despite past errors. And know that if we do make a mistake or find that a particular basket has some holes in it, we can choose to use it as a learning experience.... and we can ask for help from someone we trust if we need it.