The Christian's Great Interest (1658)

Guthrie, William The Christian's Great Interest (Puritan Paperback Series. Carlisle, PA: The Banner of Truth Trust). 10013
"It describes in a simple, clear and attractive style what it means to be a Christian, and how to become one. Guthrie was a master spiritual physician, and his wisdom appears on every page of this outstanding work." -- Publisher's Annotation
" 'I am finishing Guthrie,' wrote Thomas Chalmers, 'which I think is the best book I ever read.' And speaking of the same book John Owen once declared: 'That author I take to be one of the greatest divines that ever wrote. His book is my vade mecum. I carry it always with me'." -- William J. Grier. A Christian classic.
The Christian's Great Interest by William Guthrie

http://ccel.wheaton.edu/g/guthrie/interest/int.htm
The Christian's Great Interest (Your Salvation,) William Guthrie

http://www.e4.net ( )

I've never found the title to be particularly transparent, but that shouldn't detract from the value of this little book.

Recommended by John Owen and Thomas Chalmers and having stood the test of time (first published in 1658), it deserves to be widely read.

It describes in plain terms what it means to have experienced the saving grace of God - how to recognise the process of effectual calling in your own life, and how to differentiate between genuine heart religion versus experiences which fall short of a saving acquaintance with Christ.

And although it's so short, it still manages to squeeze in a very helpful section on the unpardonable sin (and what it's not!)