This is the post #30 of the Calvin's Institutes summary series.
Calvin identifies 5 differences between the Old Testament and the New Testament. He means the Law given by Moses when he says the Old Testament in this chapter. The five differences are:
1) In the OT times, God willed that people would direct their minds to the heavenly things in visible and tangible things, whereas in the NT, He wants us to meditate on the heavenly things directly.
2) In the OT, only the images and shadows showed, whereas in the NT, the very substance is shown.
3) The OT was literal, while the NT is spiritual. (My note: this was a bit hard to understand.)
4) The OT bound the conscience of the people, while the NT frees it.
5) The covenant of grace was confined to Israel in the OT times, but now, it is open to all nations.
These differences don't indicate there is a change in God, but it is the consistent, never-changing God who accommodates to people who change, and also according to God's own deep and infinite wisdom.