Longitudinal themes, such as human depravity, redemption by grace, and sacrificial atonement, stretch from Genesis to Revelation. It is longitudinal themes that bind the Bible, both Old and New Testaments, together. Without themes that run the full breadth of Scripture it would be difficult to hold all sixty-six books together as a coherent canon. As it is, however, the very presence of these themes makes it impossible to tear the Bible apart. The uniting presence of these themes demonstrate that both Old and New Testaments work together to give us a full revelation from God.
To preach longitudinal themes the preacher must be able to trace a theme throughout Salvation History and also be able to show its apex in Christ. For example in the wake of being cursed by God Adam looks at his wife and names her Eve, which means Life. God had just pronounced death on the human race and Adam names Eve the mother of all the living (Gen 3:20). This is the beginning of the theme of salvation through childbirth (1Tim 2:15). From Eve to Mary this theme runs like a river through the middle of Salvation History. In the face of cursing and death is hope and new life until Messiah is born. Jesus confirms Adam’s statement by offering His life as a ransom for many, thus bringing many sons to glory (Heb 2:10). Eve truly is the mother of all the living because she is a mother of the Messiah, who gives life to those who receive grace by faith.
Longitudinal themes demonstrate that the Gospel is presented throughout the whole of the Bible, not only in the New Testament.
 Clowney, Preaching Christ in All of Scripture, 35; Greidanus, Preaching Christ from the Old Testament, 222.