Your word is worth a lot. Even if you are the most broke man on earth, you still have your word to go by. When you give someone your word you will get something done by an agreed-upon date, the other person will hold you to it because they trust you. Also, because they don’t have anything else to go by.
However, if someone continues to mislead and doesn’t fulfill the promise, then the value of your word begins to deteriorate. Similar to trust, building that credit up again will take time. Earning respect and credibility takes time — losing it is very easy. With any new person, they typically start with a blank slate and then over time they are able to prove their accountability.
Don’t let people down and give them a reason to doubt you. Always follow through on your word and have effective two-way communication.