J.I. Packer clearly explains the doctrines of God’s sovereignty (that nothing happens outside of God’s will, including the actions and responses of humans) and human responsibility (both in being accountable for sin and response to the gospel, and in spreading the message of the gospel to others that they may be saved) as two truths that cannot be cancelled out by the other and need to be upheld. He then goes on to explain the significance of these truths on evangelism, as well as explaining what evangelism is and critiquing practices and opinions of evangelism.
It’s quite short, though I had trouble getting through it quickly because I hate leaving a chapter unfinished, and chapter 2 is 50 pages long, though I decided that finishing sections under headings would work.
You’re left with the weight of the responsibility, charge and privilege to share the gospel with unbelievers, but comforted by the fact that we’re not in control of their responses; God is. There is also a bit of rebuke (for me, at least) in examining your attitude to sharing the gospel, that I should not be hesitant but have a sense of urgency.
A bonus is that it’s less than $5 at Koorong.