Questions & Answers

I am thankful that you have the opportunity to speak with this gentleman who is questioning God's goodness and apparently wrestling with a burdened conscience as well. Your brief description of his questions may well indicate that he has not been served with law and gospel in an adequate way and he could use help in trusting God's goodness above and beyond God's use of sinful actions (like war and hatred) in this world.

I would begin by focusing primarily on the reality and universality of human sin and God's ultimate solution to human guilt through Jesus Christ and his saving work for us all. This is not a direct answer to the question of participating in war as a soldier nor the reality that God allows "innocent" civilians to suffer during wartime, but it sets a foundation that will be needed to allow this gentleman to trust God's promises and divine wisdom in ruling the world. If we do not trust God as our Savior from sin and guilt, we will not trust his promises that he allows sin and wicked deeds to take place and then uses them for good purposes (that go beyond our ability to understand fully.)

While the Bible records many examples of war, violent deaths, civilian casualties, and military high and low points—and all of these may be useful to help demonstrate how God works providentially in this world, the quickest answer is perhaps simply to say this:

1. When you serve as a faithful soldier representing your country in a just war (with a just cause, appropriate means, etc.), God only asks that you obey the civil authorities. See Romans 13:1-7. So if this man's conscience is troubling him about serving as a soldier, this might help. (But he still needs to focus on Christ regardless).
2. When it comes to wicked and most unpleasant deeds, God may at any time 1) forbid or prevent them, 2) allow them to take place (giving means and opportunity but not sinful motive), and if he allows them, 3) limit and direct them for his broader purposes for everyone involved, and 4) use them for the ultimate good of his dear people (believers) and to serve his ultimate glory. In doing all of this he acts in ways that may make no sense to us at the time. Remember the day we call "Good Friday." For a time it appeared to believers as horrible, unacceptable, and evidence God had lost control. But it was very "good" indeed and was a part of God's master plan to deal graciously with his people and to deal severely with unbelievers.
3. When we learn God's love and goodness in Jesus Christ and receive the gift of Christian faith through the Holy Spirit in the gospel, he allows us to walk by faith, not by sight. That is, we learn to trust divine promises and assurances when we cannot "prove" that things are fitting and good in the long run. For this former soldier, as a forgiven sinner relying on Jesus Christ, he will be led to trust that his killing in war was serving God's purposes—to bring fellow believers among the enemy to glory, to serve God as his instrument of judgment for those who despised the gospel, to demonstrate the evil of war and value of peace so that others involved may seek divine wisdom and comfort and encouragement through the gospel that is intended for all mankind, etc.
4. The biggest temptation your friend faces is what everyone asking these kinds of questions faces: the temptation to allow human sentiment and judgment on what is good and bad, right and wrong, loving and unloving to stand in judgment on divine providence and decisions on those issues. When we are brought to trust the work and promises of Jesus Christ, we also learn to stand in awe of our good and gracious God rather than to stand in judgment of him.