Basically, the statement is a snarky bit of ignorance, whicn revels in its complete non-understanding. Der Trihs is certainly… a fine example of this particular attitude. He hates and fears what he doesn’t understand. He once believed he would be in a Christianist Concentration Camp for atheists for the last decade was out.
I’ll ignore the first part, since at least it betrays a only a completely inadequate understanding fo something which really is hard for humanis to wrap their tiny minds around.
The second is a lot more complex, and therefore much more easily comprehended. It’ salways the simplest things which are hardest to understand.
One option: Jesus volunteered to pay the price for humanity, since it was so heavy we couldn’t ever make good on the debt. This has the advantages of being very easy to understnd, even if it is not very satisfying intellectually. This is usually the “kid’s” version of Christianity, and many Christians never bother to educate themselves on other concepts. Thus, they remain childish in spite and reject Christianity because it’s not “adult” enough.
Another option: God is seen as being perfectly just as part as perfectly good. As such, He can’t simply “let humans off” a bit. Moreover, even if He wanted to (which he definitely doesn’t, as it would be unjust) He can’t just ignore that evil. It will have to be dealt with one way or another. Therefore, He became Jesus (whom He is always becoming and who goes before the Father) and as a man took the punishment we had earned and took our sins upon Himself.
A third option: Humanity, in rejecting God and trying to find other hapiness, had tainted itself beyond direct salvation. God might fix this by force, but only by a sort of spiritual rape which He would never even consider. But He always wins in the end, and by becoming Jesus change the fundamental nature of humanity. We are now His adopted Sons and Daughters. We are called to dress up as Christ and become not merely lowly humans, but Kings and Queens over all Creation.
Christians ultimately disagree on exactly why it worked or what Jesus did. We agree that it did work, and gave all of mankind possibilities undreamt of before then. What those are, we are still figuring out. We shall doubtless never figure it out totally within this life.