Ps. 118:8 It is better to trust the LORD than to put confidence in people.
In case you haven't noticed it yet, people will disappoint you. People will not always treat you fairly or nice. People will not always have your best interests in mind. People will not always be honest with you. In other words, people are unreliable. You must be wise in whom you trust. Trust only those who have earned the right to be trusted. And, it takes time to observe a person in action before you know whether or not they can be trusted. Don't just jump into a relationship with someone you don't know anything about. Check them out. If you need help in discerning someone's character, go to the Lord who knows the heart of every soul.
One of the problems with people is that we are all sinners. No one is going to act perfectly towards you all the time. Everyone is capable of breaking your trust in them. It is why grace is so important in our lives. Not every misstep is worthy of a broken trust. We need to extend grace to others as much as we can. There are certainly issues that arise that are worthy of a broken trust, but don't hold all people at arm's length out of fear they can't be trusted.
You may not be able to trust some people, but you can always trust in the Lord. The Lord never varies in who He is. He is absolute Truth. He is always holy. He will never let you down. He will never seek anything but your good. He will always act in a loving way toward you. The Lord is always worthy of your trust. If you will let Him, He will take care of you and bring to completion all the good He has planned for you.
You can trust the Lord with anything and everything. He will never violate your trust in Him. He always keeps do what He says He will do. He will always be who He is. Put your life in His hands. The more you learn from Him, the more confidence you will have in His trustworthiness. God earned your trust in Him at Calvary.