the idea is you name a doctrine explain it in one sentence the present two verses to support it
eg.
works cannot save a man
however good and necessary works may be they cannot save you
Eph 2:8 For by grace are ye saved through faith; and that not of yourselves: it is the gift of God:
Eph 2:9 Not of works, lest any man should boast.
Gal 2:16 Knowing that a man is not justified by the works of the law, but by the faith of Jesus Christ, even we have believed in Jesus Christ, that we might be justified by the faith of Christ, and not by the works of the law: for by the works of the law shall no flesh be justified.
OR ANOTHER EXAMPLE
works are a part of the doctrine of Christ
things like faith and love do not make good works unimportant to God or the believer, even though these works do NOT save him these good works give faith and love a chance to do something in the believers life.
Tit 3:8 This is a faithful saying, and these things I will that thou affirm constantly, that they which have believed in God might be careful to maintain good works. These things are good and profitable unto men.
Jam 2:18 Yea, a man may say, Thou hast faith, and I have works: shew me thy faith without thy works, and I will shew thee my faith by my works.