This book was written at a time when Americans had greater capacity to think. No doubt about it. I struggled through it because of its focus and emphasis on Old Testament themes with Greek formality and language.
The distinctives Snaith focuses on are The holiness of God, The righteousness of God, the salvation of God, the covenant-love of God, the election-love of God, and the spirit of God. Each one of these topics has a comparison and contrast with the Greek and Hebrew and how it results in a theology present in the New Covenant, but found first in the Old Testament. The final chapter does a great job of summarizing these and bringing it all together.
This is not a book for the modern reader to easily pour through. I suspect in its day 100 years ago it was probably more easily grasped before television and phones turned out minds to mush. If you can get a hold of this book, I suggest you do so. I got mine used from an old preachers book sale and I am beyond pleased with it.