Here's something else to keep in mind if you want to do a good job at understanding the Bible. It's one book. That might sound obvious, but there has been this persistent attitude in the Church that divides the Bible into something like two books. (In some extreme cases it's just one book, but it starts with Matthew!) Now, no one is going to come out and actually say that what we call the Old Testament is a separate book, but for too many it's easy to think of it as something that applies to another group of people, those Israelites, and to not us Christians. There are exceptions to this. We all like the Psalms. But even here, there are parts that feel like they don't fit, now that Jesus has come. These days, instead of praying that God attack our enemies - like they do in the Psalms - we're supposed to love them. So, there are even parts of the Psalms that were for someone else and not for us. So, in one way or another, there are at least two parts to the Bible and only one part is really meant for us.
The assumption is that there has been this cataclysmic change. It's as if we're starting all over. Whatever God was doing in the first part of the Bible, He's doing something completely new now. After all, Jesus has come.
To be sure, there has been change from the first part of the Bible to our day. So, we can enjoy a good ham sandwich on rye - with the right kind of pickle, of course! Moses couldn't do that. But there were changes even within the history of the earlier part of the Bible. Abraham could have had a ham sandwich, too. And, in fact, even Moses could have before Israel showed up at Mt. Sinai. There has also been change since Jesus arrived and left. For the longest time after Jesus' ascension, the Church was limited to Jews. And the (Jewish) Christians at that time thought that that was the way that it was supposed to be. But that changed. The Church used to have apostles. But no longer. So, change is not limited to differences between the first part of the Bible and the second. There's change throughout. But those changes don't require us to divide the Bible up. We need to recognize what has been changed and what hasn't. The Bible is one book.
So, when we think about issues like the nature of worship, the status of children, the character of God and how we are to pray about our enemies, we need to consider what the Bible has to say, the whole Bible.
So, when we think about issues like the nature of worship, the status of children, the character of God and how we are to pray about our enemies, we need to consider what the Bible has to say, the whole Bible.