Two parts, one unfolding story
The Bible’s two main parts are called the Old Testament and the New Testament. Testament means covenant, a committed promise or relationship. The Old Testament begins with creation and follows God’s work through Abraham, Moses, David, Israel’s kings, poets and prophets.
It contains many kinds of writing: history, songs, prayers, wisdom, law and prophecy. Its story is honest about human failure, yet it keeps showing God’s faithfulness. Through Jeremiah, God promised a new covenant in which he would work within his people, not simply give them commands from outside (Jeremiah 31:31-33).
Behold, the days come, saith the Lord, that I will make a new covenant with the house of Israel, and with the house of Judah:
What the old covenant involved
God made important promises before Israel became a nation. He told Abraham that blessing would reach all families of the earth through him (Genesis 12:2-3). Later, after bringing Israel out of Egypt, God made a covenant with them at Mount Sinai through Moses.
At Sinai, Israel was called to listen to God and live as his treasured people, a kingdom of priests and a holy nation (Exodus 19:5-6). The law that followed gave Israel a distinct pattern of life and worship. It taught them about God’s holiness, justice and mercy, while sacrifices showed the seriousness of sin and the need for forgiveness.
Now therefore, if ye will obey my voice indeed, and keep my covenant, then ye shall be a peculiar treasure unto me above all people: for all the earth is mine: And ye shall be unto me a kingdom of priests, and an holy nation. These are the words which thou shalt speak unto the children of Israel.
Jesus and the new covenant
The New Testament opens with four accounts of Jesus’ life, teaching, death and resurrection. It then tells how the early church spread the good news, offers letters to struggling Christian communities, and ends with Revelation’s vision of God’s final renewal.
Jesus did not dismiss Israel’s Scriptures. He said that he came to fulfil the Law and the Prophets, bringing their purpose to completion (Matthew 5:17). At his last meal with his disciples, he described his coming death as the foundation of the new covenant (Luke 22:20).
For Christians, this means reconciliation with God rests on God’s grace shown in Jesus, not on someone managing to keep every command perfectly. Faith leads into a changed way of life, but it begins with a gift received, not a score earned (Ephesians 2:8-10).
Likewise also the cup after supper, saying, This cup is the new testament in my blood, which is shed for you.
Why Christians read both
The Old Testament gives the New Testament its setting. Its promises, sacrifices, psalms, kings and prophets help explain why Jesus’ birth, ministry and death matter. Without that background, words such as Messiah, covenant and Passover can feel disconnected from their story.
The New Testament shows Christians how they understand those earlier Scriptures in the light of Jesus. Faithful Christians do differ over how particular Old Testament laws apply today, especially laws tied to Israel’s national life and temple worship. Still, Christians broadly recognise the Old Testament as Scripture that teaches about God’s character, wisdom, justice and human need (2 Timothy 3:16-17).
A good place to start is one of the Gospels, such as Luke or John. As you read, notice the links back to Israel’s story. The two Testaments are different, but they tell one long story of God drawing people back to himself.