Basically, the reason Jesus had to die for our sins was so that we could be forgiven and go to be with the Lord. Jesus is God in flesh (John 1:1,14;Col. 2:9) and only God can satisfy the Law requirements of a perfect life and perfect sacrifice that cleanses us of our sins.
All people have sinned against God. But, God is infinitely holy and righteous. He must punish the sinner, the Law- breaker. If He didn't, then His law is notLawfor there is no law that is a law without a punishment. The punishment for breaking the Law is death, separation from God. Therefore, we sinners need a way to escape the righteous judgment of God. Since we are stained by sin and cannot keep the Law of God, then the only one who could do what we cannot is God Himself. That is why Jesus is God in flesh. He is both divine and human. He was made under the Law (Gal. 4:4) and He fulfilled it perfectly. Therefore, His sacrifice to God the Father on our behalf is of infinite value and is sufficient to cleanse all people from their sins and undo the offense to God.
The following outline is an attempt to break this down, step by step, using scripture and logic. I hope that it helps you understand why God is our savior and not some created thing. Also, I hope that it helps you understand that you must trust in Christ alone for the forgiveness of your sins; that you can do nothing on your own to merit salvation from God.
Gen. 1:1, "In the beginning God created the heavens and the earth."
God is infinite
Psalm 90:2, "Before the mountains were born, Or Thou didst give birth to the earth and the world, Even from everlasting to everlasting, Thou art God."
Psalm 147:5, "Great is our Lord, and abundant in strength; His understanding is infinite."
Jer. 23:24, "Can a man hide himself in hiding places, So I do not see him?” declares the Lord. “Do I not fill the heavens and the earth?” declares the Lord."
God is holy
Isaiah 6:3, "And one called out to another and said, “Holy, Holy, Holy, is the Lord of hosts, The whole earth is full of His glory.”
Rev. 4:8"And the four living creatures, each one of them having six wings, are full of eyes around and within; and day and night they do not cease to say, "Holy, holy, holy, is the Lord God, the Almighty, who was and who is and who is to come."
God is righteous
Neh. 9:32-33, "Now therefore, our God, the great, the mighty, and the awesome God, who dost keep covenant and lovingkindness, Do not let all the hardship seem insignificant before Thee, Which has come upon us, our kings, our princes, our priests, our prophets, our fathers, and on all Thy people, From the days of the kings of Assyria to this day. 33“However, Thou art just in all that has come upon us."
2 Thess. 1:6, "For after all it is only just for God to repay with affliction those who afflict you."
Therefore, God is infinitely holy and just.
Furthermore, God speaks out of the character of what He is.
Matt. 12:34, "...For the mouth speaks out of that which fills the heart."
God spoke the Law
Exodus 20:1-17, "Then God spoke all these words, saying, 2 “I am the Lord your God, who brought you out of the land of Egypt, out of the house of slavery. 3 “You shall have no other gods before Me...."
Therefore, the Law is in the heart of God and is a reflection of God's character since it is Holy and good.
Rom. 7:12, "So then, the Law is holy, and the commandment is holy and righteous and good."
Furthermore, to break the Law of God is to offend Him since it is His Law that we break. This sin results in an infinite offense because God is infinite.
Furthermore, it is also right that God punish the Law breaker. To not punish the Law breaker (sinner) is to allow an offense against His holiness to be ignored.
Amos 2:4, "Thus says the Lord, “For three transgressions of Judah and for four I will not revoke its punishment, because they rejected the law of the Lord And have not kept His statutes."
God says that the person who sins must die (be punished). The wages of sin is death.
Ezekiel 18:4, "Behold, all souls are Mine; the soul of the father as well as the soul of the son is Mine. The soul who sins will die."
Rom. 6:23, "For the wages of sin is death, but the free gift of God is eternal life in Christ Jesus our Lord."
The sinner needs to escape the righteous judgment of God or he will face damnation.
Rom. 1:18, "For the wrath of God is revealed from heaven against all ungodliness and unrighteousness of men, who suppress the truth in unrighteousness."
Matt. 25:46, "And these will go away into eternal punishment, but the righteous into eternal life."
But, no sinner can undo an infinite offense since to please God and make things right, he must obey the Law, which is the standard of God's righteous character.
Gal. 2:16, "...by the works of the Law shall no flesh be justified."
Gal. 2:21, "I do not nullify the grace of God; for if righteousness comes through the Law, then Christ died needlessly."
But the sinner cannot fulfill the law because he is sinful (in the flesh).
Rom. 8:3, "For what the Law could not do, weak as it was through the flesh, God did: sending His own Son..."
Since the sinner cannot fulfill the law and satisfy God, it follows that only God can do this.
This is simple logic. If we are unable to fulfill the Law, then we will be punished by it. But, since God desires us to be saved, the Law must be satisfied. Since we cannot keep the Law and it must be satisfied, then the only one capable of keeping the Law must keep the Law: God.
Jesus is God in flesh.
John 1:1,14, "In the beginning was the Word, and the Word was with God, and the Word was God.... 14 And the Word became flesh, and dwelt among us, and we beheld His glory, glory as of the only begotten from the Father, full of grace and truth."
Col. 2:9, "For in Him all the fullness of Deity dwells in bodily form."
Jesus was also a man under the Law.
1 Tim. 2:5, "For there is one God, and one mediator also between God and men, the man Christ Jesus."
Gal. 4:4-5, "But when the fullness of the time came, God sent forth His Son, born of a woman, born under the Law, 5in order that He might redeem those who were under the Law, that we might receive the adoption as sons."
Jesus became sin for us and bore our sins in His body on the cross, thus fulfilling the Law.
2 Cor. 5:21, "He made Him who knew no sin to be sin on our behalf, that we might become the righteousness of God in Him."
1 Peter 2:24, "and He Himself bore our sins in His body on the cross, that we might die to sin and live to righteousness; for by His wounds you were healed."
Rom. 8:3-4, "For what the Law could not do, weak as it was through the flesh, God did: sending His own Son in the likeness of sinful flesh and as an offering for sin, He condemned sin in the flesh, 4so that the requirement of the Law might be fulfilled in us, who do not walk according to the flesh, but according to the Spirit."
Therefore, salvation is by grace through faith since it was not by our keeping the Law, but by Jesus, God in flesh, who fulfilled the Law and died in our place.
Eph. 2:8-9, "For by grace you have been saved through faith; and that not of yourselves, it is the gift of God; 9 not as a result of works, that no one should boast."
Gal. 3:13, "Christ redeemed us from the curse of the Law, having become a curse for us — for it is written, "Cursed is everyone who hangs on a tree."
Eph. 5:2, "and walk in love, just as Christ also loved you, and gave Himself up for us, an offering and a sacrifice to God as a fragrant aroma."