First, we must understand that everyone sins.  Even people who do not believe in the Bible acknowledge that there are certain things people should not do against each other ~lie, cheat, steal, etc.  Many call those things sin.  There is always some sort of punishment against such, even in societies who do not believe in the Bible.  The person who does things against others over and over eventually is condemned to isolation or death.  Romans 3:23 and 6:23 sum it up,  “All have sinned….the wages of sin is death.”


            Second, heaven is God’s home, not ours.  Whether or not people acknowledge the God of the Bible, they normally acknowledge this second fact also.  God has a “door” into His home just like we have doors into our home.  God is not obligated to open the door to just anyone knocking on it, any more than we are obligated to open the door to just anyone knocking on our door.  God is not obligated to let just anyone into his home, any more than we are obligated to let just anyone into our home.  Heaven is God’s home, not ours. 


            Third, since God is Goodness and Love (even people who do not believe in the Bible acknowledge this), He cannot exist amidst Sin and Hatred.   Therefore, logically, the only people allowed into God’s home ~ heaven ~ must be perfect.


Imagine mankind as being a composite person.  Mankind was in an infant stage during the Patriarchal Age ~ what we identify as the centuries before the Law of Moses was given.   There were few religious regulations to keep.  The religion of family members was led by the oldest man, the patriarch. 


They did not go anywhere to worship; they just worshipped at home.  Mostly mankind prayed to God, tried to be good, and made periodic blood sacrifices, making animals their substitute to die in their place for their sins This is found in Genesis of the Bible


            But even with only a minimum required of mankind during its infant stage, mankind couldn’t get it right, couldn’t be perfect.


            Then mankind entered the childhood stage.  Children require a lot of rules.  So God, through Moses, gave the Jews over 600 commandments (not just the Ten that people most often think of) so we could know exactly what we should do to become perfect.  (They’re found in Exodus-Deuteronomy and called the Law of Moses.)  And the rest of the world he left without the rules, just to give them a chance to try to be perfect on their own.  The Jews offered periodic blood sacrifices of perfect animals without blemish as substitutes to die for their sins.


            But those blood sacrifices had to be made over and over because neither the Jews with their 600 plus commandments nor those nations left on their own to figure out their own system, were able get it right, to be perfect.


            Then mankind entered the adolescent stage.  Generation after generation of those given the Law of Moses rebelled against them and decided to be like the nations who had not been given those laws.  So there was a mixture of obeying God on what people wanted to do, and not acknowledging what people did not want to do.  This is found in the history books of Joshua-Chronicles  and most of the prophets of the Old Testament 


            But neither the Jews whom the prophets warned, nor the nations near the Jews whom they also warned paid any attention.  They did things their way, pretty much gave up acknowledging sins, and so couldn’t get it right and were unable to be perfect


            Finally mankind entered the adult stage.  This is when they were willing to be quiet and acknowledge, “We just can’t get it right.  We don’t know how to be perfect.”  This occurred during the last of the history books (Ezra–Esther) and prophecies of Old Testament (Haggai-Malachi).  The Jews and proselytes  returned to making blood sacrifices of unblemished, perfect animals as substitute punishment for their sins.  But, as always, they had to do it over and over, because they sinned over and over.


            Now mankind was ready for Jesus.  Jesus kept the Law of Moses perfectly.  He never sinned (Hebrews 4:15).   He was perfect and was called the Lamb of God (John 1:29).  Finally mankind had the perfect substitute for their sins ~ not a perfect animal but a perfect human.  He was also God in the flesh (John 1:1) and only God is Good (Matthew 19:17) and only God is Love (I John 4:16) ~ perfection.


            And so Jesus laid down on the altar of the world ~ the cross ~ and became our substitute, our perfect blood sacrifice for our sins.  But he didn’t stop there.  He did one other thing that is impossible for us to do on our own:  He came back to life!  He overcame both sin and death. 


Then God told the world if we will imitate what Jesus did for us, he will consider us perfect and sinless also. 


Romans 6:1-4 explains that, just as Jesus died on the cross for our sins, we die to our sinful nature.   Then, just as Jesus was buried in his tomb, we are buried in a watery tomb of baptism.  And just as Jesus was raised up out of his tomb the Savior, we are raised up out of our watery tomb the saved!


Now God considers us family (Romans 8:17).  He lets family into his home.   And the door?  The door is Jesus (John 10:9) through whose death, burial and resurrection we enter heaven.   And that is why Jesus had to die.  We will thank him for eternity.