One issue in the reading and understanding of Scripture is the extent to which verses outweigh themes and vice versa. Most Christians, of whatever persuasion, are liable to trumpet a verse to settle an issue. Having trouble with opposition? "Love your enemies" might be quoted to us. Why should I bother to go to that community meeting on a wet and windy night? "Love your neighbour as yourself" our spouse might prod us with. Of course there are other instances you will think of re controversial issues such as the ordination of women and acceptance of same sex partnerships.
But we also, perhaps as it suits the argument (!!), bring out themes to settle an issue. Should Christians go to war or not? Hard to find one text which settles that issue, but there are great themes running through the Bible concerning service of our country, to say nothing of working for justice and the protection of the innocent, which yield support for a 'just war theory'. Does a stillborn baby go to heaven? Hard to think of a verse which answers that question. Easier to find themes of love, grace, and mercy in the heart of God running through Scripture to draw on.
Doug Chaplin of Clayboy has a nice post on Themes and Verses.