You have likely heard the saying “Fool me once, shame on you, fool me twice, shame on me”.
If someone has repeatedly deceived you, how can they be trusted? I’m not sure that they can. You may want to look at the conditions or the severity, based on your perspective, of the deceit. If it is in deceiving you out of material possession (money etc.) you can decide that they must need it more than you do or you don’t place value in it. But then why the deceit? Couldn’t they just ask for it?
If it is in lying about where they go or what they do you can decide to trust their judgement and figure maybe they don’t tell you so you either don’t worry or don’t give them a lecture about it later. You decide to accept that. But what is the real reason for the dishonesty? Why might they believe it is best or easier to lie or tell you otherwise rather than to simply be truthful? Are you okay with it if your worst imagined scenario was true? Only you can decide that for yourself.
Your desire to “sincerely trust” is your choice, but you must allow the other to be as they are and leave their reasons to them. If you can honestly be alright with that, then there is no problem
Have others had this experience of having difficulty trusting someone again? What did you do about it?