The question was put to me, "Why memorize the names of the Patriarchs? Why not rather spend your time memorizing some verses that will help you in your walk with the Lord?" My answer is this;
1. God seemed inclined to give us the list of those names and their characters many times in Scripture. It seems to me that God is placing special emphasis on something when He repeats it again and again, I don't think He is big on wasting words. When He repeats something, He really wants us to get it.
2. They are our fathers. If we have been adopted into Christ, then His history has become our history. We have been brought into relationship, into covenant, with all that God has worked in before. Honor your father and mother, the Lord tells us. So we learn about them, but not just about them; we learn what God has done in history as we learn about them. And learning all the whats, whos, wheres, etc. in the Bible DOES help us in our walk with the Lord, because we learn who He is and what He does and how He works.
3. For little kids about 4 years old this song is a fun challenge. They haven't had a great grasp on how to speak for very long, but now, a challenge! They love it. And besides, I'd much rather fill my kids heads and hearts with "Abraham, Isaac, and Jacob," than with "heavenly sunshine" or "arky, arky" kinds of songs. Abe and company, that is real stuff; the other stuff is fluff that someone made up. Little kids are knowledge sponges, fill them up with Bible, and not with distractions.
4. Little kids can grasp a story, or a list of names, much better than they can grasp an abstract concept like justification by faith alone. That is how God built us; we learn by stories when we are little, we learn to think abstractly in our teens. I'm quite sure that is why God built the Bible with so many stories in it, so that His children would remember.