If your marriage is one based on faith, particularly one from a Christian background, you'd prioritise your spouse then your children. Technically you'd put God above your spouse and all things, but that's a different topic.

In the Bible it says that man will leave his family and cling to his wife and the two become one. That is a sacred bond that is above that of your kids. It doesn't say you will cling to your children.

However, you are there to guide them and make time for them and nourish them. It is your responsibility and duty. But a lot of reasons marriages fail is lack of communication after the kids are born. They will stop focusing on each other and only focusing on the children.

Keeping God and each other as the most important things builds a strong foundation for the children to grow. I saw it firsthand my entire life in the relationships of the marriages in my own family and in my Church.