Christian Ethics by Norman Geisler was written in 1989. I’ve known many people who have read this book over the years, but never bothered to do so myself until I saw it on sale for a deep discount! I found it to be a great introduction to ethical systems and pressing moral issues.
Geisler starts by looking at various ethical systems such as antinomianism, situationism, utilitarianism, generalism, and variations of absolutism (these are the names he gives these views, which are not exactly my preferences). He concludes that the Bible teaches a deontological view of ethics. When it comes to the question of whether moral duties ever conflict and how we are to respond, he argues for the “greater good” view in which moral conflicts are real, and we do the greater good when we choose to lesser of the two evils.