Law and Gospel in the Old and New Testaments

In the Old Testament are many promises, which are nothing else but the Evangelion or gospel, to save those that believed them from the vengeance of the law. And in the New Testament is oft made mention of the law, to condemn them which believe not the promises. Moreover, the law and the gospel may never be separate: for the gospel and promises serve but for troubled consciences, which are brought to desperation, and feel the pains of hell and death under the law, and are in captivity and bondage under the law. In all my deeds I must have the law before me, to condemn mine imperfectness. For all that I do (be I never so perfect) is yet damnable sin, when it is compared to the law, which requireth the ground and bottom of mine heart. I must therefore have always the law in my sight, that I may be meek in the spirit, and give God all the laud and praise, ascribing to him all righteousness, and to myself all unrighteousness and sin. I must also have the promises before mine eyes, that I despair not; in which promises I see the mercy, favor, and good-will of God upon me in the blood of his Son Christ, which hath made satisfaction for mine imperfectness, and fulfilled for me that which I could not do.

~~William Tyndale, A Pathway Into the Holy Scripture.