Necessity of the ransom
Christianity confuses some people.
The death of Jesus, the only begotten son of God, paid for the sins of humankind. Some skeptics wonder why this was even necessary: An all-powerful God could have defined the universe's rules such that no ransom had to be paid at all. This would allegedly have saved his son from needless suffering. So I asked an elder of my congregation to explain why a ransom has to be necessary.
First, Jehovah is a god of justice. (Psalm 37:28) Man is created in God's image (Genesis 1:27) and it is God's job to decide what's appropriate. There need to be consequences for people's actions or people won't have any incentive to do things that please God. The rule that "the wages sin pays is death" (Romans 6:23) is there to give people a chance to show that they can handle their free will.
And these rules need to be consistent to be fair. If God were to change that rule, there would be no way to answer the challenge that Satan brought in Eden, namely an allegation God does not want what is best for mankind and is withholding things from mankind. (Genesis 3:1-5) In effect, Adam and Eve stole from God: they took something belonging to God despite God's order not to. They saw right and wrong and chose wrong. Later, Satan taunted Jehovah about Job, claiming that Job would give up on God if God were to allow certain alleged unfair advantages to be taken away. (Job 1:7-10) And even Paul, like Adam and Eve, "was ignorant and acted with a lack of faith." --1 Timothy 1:13.
God's purpose with mankind is that people "should be saved and come to an accurate knowledge of truth," and Jesus is how this is accomplished. (1 Timothy 2:3-6) Just forgiving sin without payment wouldn't help give accurate knowledge, nor would it free our senses from the snare of the Devil. (2 Timothy 2:25-26) And without this accurate knowledge, there would be no way to answer Satan's challenge, and more people would agree with the sentiment behind this challenge and turn away from God.
Imagine a contest about keeping a hand on a car to win the car. If a competitor didn't lose when pulling his hand off, the others wouldn't think that fair. But if he came to the next contest and won legitimately, it'd still be fair to award him the car. In this analogy, Jesus started a new contest.