It's the only way that anything adds up. When you have a covenant of works that requires perfect obedience, and the one who breaks that covenant (Adam) represents all of humanity in himself, causing a collective curse upon the entire human race, the only way that sin can be eradicated is by having one who perfectly keeps that same covenant (Christ) voluntarily lay down his life in order to reverse the curse. It is impossible for any naturally conceived human being to do what is not in his/her nature, and perfectly keeping the law intrinsically and extrinsically is not in the nature of Fallen Mankind. Jesus' perfect obedience fulfilled The Law, and his death and resurrection became the new archetype (the New Adam) by which the curse of death is lifted from mankind, and his divine person, as part of the Holy Trinity makes it all possible.
It is all perfectly understandable, it is all perfectly logical. Those who don't think it adds up think that way because, deep down, they don't want it to add up. Such is the intellectual manifestation of sin, turning reason against the truth.
Consult The Gospel of John, chapter 1, among other key parts of the New Testament. If Christ is not God, the entire revelation of both the OT and the NT are a complete sham. I get this "Jesus was a good person/teacher but he wasn't God" nonsense from modern "thinkers" all the time, completely unbeknownst to them that this statement makes Christ a liar by necessity, hence he wouldn't be such a good person/teacher after all.
"Jesus saith unto him, I am the way, the truth, and the life: no man cometh unto the Father, but by me." (John 14:6)
Tell me, what makes you think that you have the standing to address God the Father directly? At no point in all of scripture does The Father address any man, patriarch, prophet or apostle directly, but always through either The Son (The Word, through the prophets in the OT), or in the pouring out of his Spirit (The Holy Spirit, another different subsistence of the Trinity, but one and the same in substance). Which one of those 2 are you again?