Modeling behavior can be a powerful way to teach especially since children have a way of zoning us out when we're always talking to them.
A good explanation would be - what a grownup does, rather than what they say, is what a child will learn best from.
Hence the saying "actions speak louder than words", applies quite correctly in the raising of children. That means we have a huge responsibility to behave in a way that we want them to behave.
Modeling is one of the concepts Dr Maria Montessori thought of very early on. She was teaching children in Italy and observed that children copied everything she did, and thought that this was a wonderful concept and a way of teaching them without using words. A lot of the Montessori lessons are therefore done without the use of words. The child is watching you and focusing more on what you're doing than what you're saying to them.
It sounds quite obvious but let's take a step back and look at some of the things we do subconsciously that might be setting a harmful example to our children.
One thing to think about for example - when you're driving the car, don't text and drive, be focused on what you're doing because when your child is ready to learn to drive, they'll be following what you've modeled for them all these years. Imagine how worried we would be to learn that they are driving with their devices in hand instead of eyes on the road. But if they've grown up to see us do so, it would be hard to teach them otherwise.
You can use your child’s constant observation and curiosity as a chance to demonstrate appropriate behaviors such as good manners, empathy, sharing, and respect for others. It will reflect positively on them.