My husband and I have different parenting styles and can't come to an agreement. How can we fix this?
Many parenting books recommend an approach to parenting that is empathetic yet direct. It's easy to read these approaches or hear about them and then decide what sort of parents you will be like. It's a whole other story when we try to live it out, however, and you two are discovering why.
There are many ways in which this situation could be tackled. The focus here is to identify what sort of person you want to raise and agree on it. It seems best that you two come together, do the aspects of parenting that you can decide on and focus less on how to get there? The sort of child, a future adult you both want can often be agreed on more easily. For example, you want an empathetic adult, who cares for others, takes care of his future wife and children, has hobbies, and is willing to sacrifice the lesser things for the greater. You want an adult who will positively contribute to society, be slow to react, and be able to tolerate difficult emotions rather than run and try to fix or escape all the time.
These are the desired characteristics I hear from people who are struggling in life. People, maybe even you two, may have been raised in homes that did not model the above behaviors, and therefore these ways of life were not fathomable to the child. So, as the parents of this future adult, you want to be able to model these traits, not just speak on them. This tiny brain in your midst is watching every move and isn't able to justify behaviors through stress or circumstance as adults do. So, the first thing for you two is to talk about how you think the child sees things. What do you think the child is noticing?
You can play this game with the child while in the car to and from somewhere. You can look in the rearview mirror and ask the child, "If I were you and you were me, what would you see." In the car, the child might answer something like the windshield is what they would see, and you, through their eyes, would see the car's back seat. It's an exercise that draws kids out of their own heads.
Another approach to parenting, especially to a child who talks back, is to ask them, "what do you think I am going to say right now?" But, you have to ask them with genuine curiosity. Ask the child reflective questions to get them to think outside themselves and put them in the headspace of what they see from you. One time my child started painting the table instead of the paper (almost anytime we paint, she does this actually), and rather than say, "we don't paint the table," she runs away laughing, which then elevated me to a command, I asked her, "what do you think I am supposed to do right now?" She looked at me and said, "don't do that." I then asked her why she would I say that, "Because it makes a mess that you have to clean up." Which then she conceded. Now, don't for a second think that was the way of things after that because they are children, exploring their boundaries, who they are how far they are going to go to discover that, so she constantly pushes (she is seven now), but she has modeled something critical.
Here's the rub, you have to find value in instilling values and model behaviors you would want to see in someone you trust as an adult. There are a million recommendations of what to do in every finite situation. The reality is you and your husband have to come together at the points you can agree and also agree to model support for the other. You are modeling what it is like to be on a team and how to work with people. If it turns into your justification for parenting versus his, and you are convinced that because yours is fitting that he is wrong, that's errored thinking and, quite honestly, egocentric (selfish).
I will say to sit down and come up with the main things you want all discussions to settle on. He is a four-year-old boy who is exploring his territory and seeing what is his and where his little kingdom stops. You two are showing him boundaries. You can start appreciating the battle because he will not lie down and give up; he fights. He wants what he sees and is willing to fight you two for it; it's commendable. However, you must show him where he stops, and you start, and he cannot infringe on that. Respect the child's behaviors (you don't have to agree, but respect), and you can approach the situation calmly and with the attitude; this is precisely what it takes to form a human these days.
Focus on a few main things each day and every interaction, and you and your spouse NEED to come together on this. Respect each other's decisions; if you cannot, you need to understand why that is and how you CAN come together. You two providing a safe environment means more than all the other things. A safe and consistent environment is critical for the child to feel safe and learn who they are. You are to provide that first and foremost.