Isn’t that obvious? To get to know each other! For the more you know about your partner, the greater the chances for a successful marriage. This is the time to find out whether you are alike in the way you look at things. This is important, for the more you are alike, the better the chance for a successful marriage.
Read more on marriage in book # 2 and # 7 in my references on my Bio Page.
Spending their lives together
People get engaged because they already know each other, and know they want to spend their lives together, yes they will learn more about that person during that time, but over time you get to know everybody more the longer you know them. That’s not why people get engaged though, they get engaged because they love each other
Getting engaged is a way of pledging or promising to be married to someone. Some sixty or more years ago when I was of marrying age, if I broke off the engagement I could be taken to court by the lady and punished for what was called Breach of Promise. There was either a fine involved and the lady could keep the engagement ring.