Strength is not tested or demonstrated during times of ease. Rather, it is during times of adversity that one finds out just how strong he is.
How would making your motive match the Lord's motive change how you approach the Christian life (from witnessing to praying to Bible reading and so on)?
Capital punishment is not confined to the Old Testament and is not done to the exclusion of God’s grace, but rather as an act of God’s just judgment.