Also, I just remembered this book my small group is going through. It does a good job of walking through the basics. https://www.amazon.com/Bible-Doctrine-Essential-Teachings-Christian/dp/0310222338/ref=sr_1_1?dchild=1&keywords=bible+doctrine&qid=1628787357&sr=8-1
It's great that your Sunday School class is studying theology. You didn't ask, but I can't help myself to tell you: please make lessons understandable to those visiting your church for the first time. As you finish your lesson, as yourself, "can a 17-yr old who has never been to church substantial understand this lesson?"
You have to go deeper sometimes than a visitor could immediately grasp, but I encourage you to take the extra steps in lesson preparation to bring down the language and concepts in a way that's accessible. Sunday School used to be the primary evangelism and discipleship program used by Southern Baptists, but we've lost a lot of that. I know it's a lot of extra work to keep it accessible yet still push your mature members. It will be worth it when a mature member feels comfortable to bring their cousin or coworker, that person hears your message, the mature member talks about it at lunch and eventually that visitor is saved.
/rant
I've liked Chuck Lawless stuff in the past.
Here is a book review of one of his books.
Combing through some of David Platt's stuff may be useful.
There are usually some good resources on Desiring God. Filter by resource type.
Here's a little fight you might like. I'm not endorsing the authors.
I own Bible Doctrine by Wayne Grudem. It's definitely not as comprehensive as his main Systematic Theology, but you can get quick takes on lots of topics. For this topic, search around for different keywords. Kindle is free and you can get a used version for really cheap.
Capitol Hill Baptist Church has all their sermons online. Spiritual Warfare is not a big topic by itself, but search the chapter that you want a sermon about and hear Dever's take on it.
Monergism is a site worth knowing about.
However, if you want some wild stuff that's actually very well sourced, try Michael S. Heiser. Try out the Naked Bible Podcast on whatever you listen to podcasts. Start at the beginning when he explains some of the basics of his approach. He's also got a lot of stuff on YouTube. I hope that you don't agree with everything he teaches, but he gives a good overview of the positions and wrestles with stuff we don't get much of elsewhere. Skip the Fern and Audrey episodes; they are boring and off topic. You can get electronic versions of his book, Unseen Realm, pretty cheap. But listen to about ten podcasts first to see if you want to go further with him. His website has a lot of resources too. He's probably going to push you on some of the Deuteronomy 32 and Psalm 82 stuff. He beats the Genesis 6 drum a lot, but he's often better sourced than orthodox views. He has a bit of a superiority complex so you have to get past that.
You might think he's the "sketchy waters" but at least give it a try if you want to wade into this stuff.
Lastly, the free version of Logos has a lot of great tools. Install it and spend some time searching through all the free books. Sign up for the free book of the month email. You won't get great stuff every month, but a couple times a year you get a great commentary for free.
I*n the same vein, the Faithlife Study Bible is free* as a part of Logos and it's free as a standalone app or web resource. On the relevant passages it tackles the spiritual realm in more detail than the ESV Study Bible.
I'm out of time but I hope this is some help. I could come up with some books I've read another time but it's been a while. There is a lot of Church History stuff out there. Look up Joachim of Fiore.
Oh, in that case I would check out Bible Doctrine by Wayne Grudem. It's pretty accessible and covers pretty much every area of Systematic Theology.
So, thinking along the lines of the book you listed, you're looking for ideas on content to cover, rather than whole books to shove in. It seems then like you're considering a miniature systematic theology covering all the basics of Christianity, coming in around 300 pages, with a decent depth but slightly favoring breadth.
Wayne Grudem published an abridged version of his systematic theology called <em>Bible Doctrine</em>, which comes in about double the desired length. This one has most of the breadth, but too much depth for the "toolkit" approach.
He also published <em>Christian Beliefs</em>, which comes in at about half the targetted length with 20 overall topics. By page count, I would expect this has the depth one would look for, but not the breadth of coverage.
I don't know that such a tool covering about 100 topics in about 2-3pp/ea. exists for reformed Christians. But, were one to be written, I imagine you could get ideas for what you'd want from those two Grudems, from the confessions, and from the catechisms.
Our toolkit could cover:
Actually, I just looked over at Calvin's Institutes and saw that, all four books together, there are exactly 100 chapters. If you could condense each chapter down to 2-3 pages while adding in more direct information about church history, you'd be well on your way to a good toolkit.
I would reccomend a book like this. It's a fairly simple read. If you want the long version he has a book bigger than a college text book. He goes step by step explaining if this is true then this is true then this is true. It covers everything from who God is, to what we know of the texts from old manuscripts like the Dead Sea scrolls.
Bible Doctrine: Essential Teachings of the Christian Faith https://www.amazon.com/dp/0310222338/ref=cm_sw_r_cp_apa_i_LIh.CbN2EXE02