I feel actually ashamed writing this because I know how important this is to Christian faith but I struggle to fully understand the meaning and reasoning of the sacrifice.
I understand we sin and Jesus died for our sins but then what exactly does that mean?
It's not like the death sacrifice stops us from sinning. Wouldn't it be better if he lived for our sins and reminded us not to?
If I have a dog and I notice all the other dogs are acting wild barking etc...does it make sense to sacrifice my dog whom I love for the bad behaviour of all these other beasts?
I know this is a very fundamental point but for some reason my brain can't actually fully comprehend the importance and meaning of sacrifice so I would appreciate some very simple explanations or books (maybe even ones directed at young people) on this topic.
Thanks!
Romans 6:23 - For the wages of sin is death, but the gift of God is eternal life in Christ Jesus our Lord
Hebrews 9:22 - And according to the law almost all things are purified with blood, and without shedding of blood there is no remission.
John 14:6 - I am the way, the truth and the life. No one comes to the Father except through Me.
You have to go back to the fall of Adam in Genesis 3. God had told Adam and Eve that they would die if they ate of the fruit of the Tree of Knowledge of Good and Evil. When they disobeyed God, they sinned, and separated themselves from God. They immediately realized this, and quickly tried to cover their newly understood nakedness with fig leaves.
Several times in Scripture God is described as being longsuffering, slow to anger, etc. Genesis 3 is the first demonstration we have of this, as he did not kill Adam and Eve on the spot, despite telling them they would die. Instead he showed them grace, declaring that the Seed of the woman would eventually smash the serpent. But God, in His nature, cannot overlook or abide by sin in any way. So death had to come in, and after He pronounced the various curses that came to pass because of sin, God killed an animal and clothed Adam and Eve with its skins. In this way, it was established that only the shedding of blood was sufficient to cover Adam and Eve's nakedness, where the fig leaf was insufficient. So it went with the sacrificial system described later on on the OT, those repeated animal sacrifices were acceptable to God, at least in a temporal sense.
But ultimately animal sacrifices could never be enough to reunite sinful man with a holy God. Enter Christ, who became man, joined us in this corrupted world, and did not sin, offering Himself in death, such that His shed, spotless blood would be adequate to cover the sins of all who believe. The significance of this is without that sacrifice, there would have been no way for man to reunite with God. In another of His mercies, at the end of Genesis 3, God kicks man out of Eden and bars them from returning, thereby preventing a now sinful man from living forever and cementing his corruption for eternity. If there is no death, there is no payment for sin. But because death came in, Christ could then die and offer His perfect blood for us. His resurrection, ascension and seating at the right hand of the Father was confirmation of God's acceptance of the sacrifice, thus opening the only way for humanity to reunite with God to eternal life, as stated in John 14.
If Christ had just been, say, a unique man on the earth who just lived forever, always there in the flesh to remind men of all generations not to sin, as I think you are getting at, that still would have left all men separated from God permanently since all have sinned.