Who made the rule that sin could only be forgiven by a blood sacrifice?

Eating the flesh and drinking the blood of a sacrificed man (symbolic or not) is an ancient cult activity.

It's part of the nature of sin that it causes death.

Also God didn't sacrifice his son. Jesus is God. So God sacrificed himself.

Bronze Age goat herders.

Adam and Eve FORCED the first animal sacrifice.....Because they went against God, God had to kill an animal to provide clothing for them to cover their shame....It must have really tore him up to slaughter one of his own loved creations...but Man was more important so he did it.

So I believe Animal sacrifice of blood was put on mankind to make us feel the pain he felt when talking the life of another....That's just my opinion.....

How sad...people just can't see and understand how the whole point of God's plan works.........I will pray that God will have mercy and open the eyes of your heart.

Jesus went to the cross willingly:

Matthew 26:53 - "Thinkest thou that I cannot now pray to my Father, and he shall presently give me more than twelve legions of angels?"

His suffering was at the hands of SINNERS, not God.

But why are you fixated on unimportant TEMPORARY pain, rather than eternal life?

Read about Issac sacrifice

Jesus was executed for saying that he was God. God did not make that decision. Jesus was God, so it was God on the cross. He knew when he incarnated himself as a human that he would rock the boat and be executed in the manner that Romans executed all rebels.

Energy.

Jesus came to the earth “to give his soul a ransom in exchange for many.” (Matthew 20:28) A ransom is the price paid to buy back, or to bring about the release of, someone or something. The verb form of the Hebrew word rendered “ransom” conveys the idea of covering, or atoning, for sins. (Psalm 78:38) The Greek word, such as that found at Matthew 20:28, was used particularly to refer to the price paid to ransom prisoners of war or to release slaves. To satisfy the demands of justice, one thing is given in exchange for another of corresponding value.Mankind came into slavery because of the first man’s rebellion against God. As shown in Genesis chapter 3, that perfect man—Adam—chose to pursue a course of disobedience to Jehovah God. By doing so, he sold himself and his yet unborn descendants into slavery to sin and death. For himself and all his offspring, Adam thus forfeited the gift of perfect human life.—Romans 5:12, 18, 19; 7:14.In ancient Israel, God arranged for animal sacrifices to atone for, or cover, the sins of the people. (Leviticus 1:4; 4:20, 35) In effect, the life of the sacrificial animal was given in place of that of the sinner. (Leviticus 17:11) Consequently, “the day of atonement” could also be spoken of as the “day of the ransoms.”—Leviticus 23:26-28.Since animals are inferior to man, however, it was “not possible for the blood of bulls and of goats to take sins away [completely].” (Hebrews 10:1-4) For a sacrifice to have sufficient value to atone for, or remove, sins permanently, it would have to be equal in value to what Adam forfeited. The scales of justice required a perfect man (Jesus Christ) to counterbalance what another perfect man (Adam) had lost. Only a perfect human life could pay the ransom price to redeem Adam’s offspring from the enslavement into which their first father had sold them. A ‘soul for a soul’ would meet the demands of true justice.—Exodus 21:23-25.When Adam sinned and was sentenced to death, his as yet unborn offspring were still in his loins and therefore died with him. The perfect man Jesus, “the last Adam,” willingly did not produce a family. (1 Corinthians 15:45) He had unborn offspring in his loins when he died as a perfect human sacrifice. Therefore, it might be said that the potential human race within his loins died with him.  Jesus took Adam’s sinful, dying family as his own. He gave up the right to have a family of his own. By sacrificing his perfect human life, Jesus repurchased all mankind descended from Adam so that they could become His family, making Him their “Eternal Father.”—Isaiah 9:6, 7.Jesus’ ransom sacrifice opened the way for obedient mankind to receive God’s mercy and obtain everlasting life. Consequently, the apostle Paul wrote: “The wages sin pays is death, but the gift God gives is everlasting life by Christ Jesus our Lord.” (Romans 6:23) We cannot help but praise Jehovah for the love and compassion associated with the ransom, provided at tremendous cost to himself and his dearly beloved Son. (John 3:16) And Jesus surely proved to be “a helper with the Father” when he was resurrected to heavenly life and presented the value of his ransom sacrifice to God in the heavens.* (Hebrews 9:11, 12, 24; 1 Peter 3:18) But how is Jesus Christ now proving to be our helper in heaven?

Original sin and free will is why Jesus had to die for our sins.