What is the difference between the old ang New Testament?

In the Old, you had to sacrifice animals to talk to God, in new, jesus sacrificed himself

Answer:

The New Testament sheds the Light of Spiritual Understanding, through Jesus Christ. upon the Old Testament scriptures, that they may be understood in the last days by the end time generations.

"...Go thy way, Daniel: for the Words are closed up and sealed till the time of the end.

"Many shall be purified, and made white, and tried; but the wicked shall do wickedly: and none of the wicked shall understand; but the Wise shall understand." (Dan.12:9-10)

"Then opened He their understanding, that they might understand the scriptures." (Luke 24:45)

"...Weep not: behold, the Lion of the tribe of Juda, the Root of David, hath prevailed to open the book, and to loose the seven seals thereof." (Rev.5:5)