God sent Jesus to earth so that He would be sacrificed in our place - redeeming us. But God sent Jesus knowing that he would die and our sins could be taken away. Why bother? Why didn't He just take them away without sacrificing His son? He is God. Secondly, why did God have this sudden turn around from punishing mankind due to Adam and Eve and save everyone? Thirdly, the covenant with Abraham states that through him all the peoples of the earth will be blessed. This says that God will like the people, but they still will not have eternal life? So many holes. Please help me. When does the Bible begin to speak about actual salvation? And why God's sudden change of mind?
Your questions imply that God had freedom of choice, and that God changes.
Why did God send His son to die for the people of the world? Why bother? Why didn’t He just take them away without sacrificing His son? He is God. The answer requires that we first understand that God is a holy person.
. . . because it is written, “YOU SHALL BE HOLY, FOR I AM HOLY.” (NASB) 1 Peter 1:16
We can read the words, but it is impossible for us to completely understand an absolutely holy person. Yes, God has emotions and a will, but He is not like us.
. . . You thought that I was just like you . . . (NASB) Ps. 50:21
He is not polluted by sin. He is one who does not violate any moral standards. He has told us that anyone who sins will die.
. . . through one man sin entered into the world . . . so death spread to all men, because all sinned . . . (NASB) Rom. 5:12
But we are also told that because God loves us He decided to rescue us by having Jesus come and die for us. This next verse tells us that we are helpless, and so God devised a plan to rescue us.
For while we were still helpless, at the right time Christ died for the ungodly. For one will hardly die for a righteous man; though perhaps for the good man someone would dare even to die. But God demonstrates His own love toward us, in that while we were yet sinners, Christ died for us. . . . (NASB) Rom. 5:6-7
The message of Hebrews 10 is that a perfectly holy person, Jesus Christ, had to die in order to take away our sins. Why did He do this? Apparently, God had no choice. No other person is morally perfect. No one else could take the punishment for our sin.
And you know that He appeared in order to take away sins; and in Him there is no sin. (NASB) 1 John 3:5
Why did God have this sudden turn around from punishing mankind due to Adam and Eve and then decide to save everyone? God did not a have a sudden turn around and then decide not to punish mankind. First, God never changes. Listen to the book of Hebrews.
Jesus Christ is the same yesterday and today, yes and forever. (NASB) Hebrews 13:8
God is always the same. Second, God had planned to do this from the beginning of time – from the foundation of the world.
Men of Israel, listen to these words: Jesus the Nazarene, a man attested to you by God with miracles and wonders and signs which God performed through Him in your midst, just as you yourselves know – this Man, delivered up by the predetermined plan and foreknowledge of God , you nailed to a cross by the hands of godless men and put Him to death. And God raised Him up again, putting an end to the agony of death, since it was impossible for Him to be held in its power. (NASB) Acts 2:22-24
God has allowed men and women the freedom to sin; but He warned Adam that if he did sin, he would deserve to die (Gen. 3:4). God wanted a relationship with us, but Adam was more interested in doing what he wanted. God knew that Adam would make this choice, and so He planned to send Jesus Christ to die for us. He had planned to send Jesus to rescue us all along, because He wants a relationship with men and women who desire a relationship with Him.
When God told Abraham that He would bless the people of the world through him (Gen. 12:1-3), He was talking about His plan to rescue us through Jesus. This becomes clearer later in Genesis 22 when God repeats the promise and adds to it. Notice in verse 18 that God says “in your seed.” In the following verse the expression “seed” refers to Abraham’s offspring, or descendents. He is talking about Jesus Christ. This point is explained in the New Testament.
And in your seed all the nations of the earth shall be blessed, because you have obeyed My voice. (NASB) Genesis 22:18
Now the promises were spoken to Abraham and to his seed. He does not say, “And to seeds,” as referring to many, but rather to one, “And to your seed,” that is, Christ. (NASB) Gal. 3:16
Hebrews 11:8-13 tells us that Abraham understood the promise that Jesus Christ would come to die for our sins.
When was the promise first communicated? The following statement was made by God to Satan,
And I will put enmity between you and the woman, and between your seed and her seed; He shall bruise you on the head, and you shall bruise him on the heel. (NASB) Gen. 3:15
Notice that the verse says the women has seed. Now we know that this is not possible, except for the virgin birth. The statement “her seed” implies that there was not a male involved in the birth of the promised one. This occurred when Mary gave birth to Jesus by the supernatural power of the Holy Spirit (Luke 2:6-38).
God wants a relationship with us. Some of us do not care, and others do. Our ancestors exercised their freedom of choice and disobeyed. God had warned them that if they chose to do that, they would deserve to die. God was not surprised. He knew this was going to happen. As a result, God had already planned to send Jesus Christ to die for us so that those who wanted a close relationship with God could have one. The plan has been in place before the foundation of the world. Do you have a close relationship with God?