From the time the tabernacle was built until the temple was destroyed in 70 A.D., the Israelites regularly offered animal sacrifices to God. The number of sacrifices made is staggering. Every day two lambs were offered, one in the morning and one in the evening. The Israelites were commanded to bring trespass offerings to the temple anytime someone sinned against God or his neighbor. If a Jew became unclean by touching an unclean thing, by having an unclean disease, by having an unclean sore or by doing one of the many things that made him unclean he was to bring a sacrifice to the Lord to be made clean. The Bible gives no record of how many sacrifices were offered each day, but if even a small fraction of a percentage of the millions of Israelites brought a sacrifice each day, then hundreds or thousands of sacrifices were made every day. On the day of passover, one lamb was sacrificed for every family in Israel. Tens of thousands of sacrifices were made on that one day alone.
To modern sensibilities this seems cruel, or worse. The temple was practically a slaughterhouse. The sacrifices were required by God for a specific and special purpose. The sacrificial system gave a constant reminder of the consequences of sin. Killing animals is disturbing. That is the point. Man was meant to be disturbed by his sin. God required the Jews to make sacrifice to Him because the killing of animals was a continual reminder of the wages of sin. “But in those sacrifices there is a remembrance again made of sins every year.” (Hebrews 10:3)
From the very beginning (Genesis 3:21) the shedding of blood was required to cover sin. “Without the shedding of blood there is no remission.” (Hebrews 9:27) When God gave Adam and Eve the command to not eat of the fruit of the tree of the knowledge of good and evil, He warned them that if they disobeyed they would die. God provided animal sacrifices as a covering for sin.
Though the sacrifices covered sin, they could never take it away. “For it is not possible that the blood of bulls and of goats should take away sins.” (Hebrews 10:4) The sacrifices of the Old Testament were a foreshadowing, a picture ahead of time, of the sacrifice that would come which would be able to take away sin. Animals sacrifices pointed ahead to the only One who could be a full substitute for sin. The sacrifices were a picture of a promised deliverer who would wash away sin. The sacrifices showed the wages of sin and pointed to the One who would take away sin forever. “But this man, after he had offered one sacrifice for sins for ever, sat down on the right hand of God.” “For by one offering he hath perfected for ever them that are sanctified.” (Hebrews 10:12, 14)