Consider Jesus the perfect Man, who perfectly fulfills the Law of God (see Mark 12:28-34). He demonstrates perfect love for his heavenly Father, and perfect love for neighbour, meaning humanity.
His perfect love for neighbour means that, after the Fall of Genesis 3, his love for men in their lost condition requires him to find a way to rescue them. They need to have their sins removed, atoned for, so that fellowship with the heavenly Father can be restored. Knowing as he does, from his own experience as the eternal Son, how delightful is fellowship with the eternal Father, and how awful is the loss of that fellowship, he cannot just sit back and allow men and women, uniquely made in the image of God, to be shut out eternally from such a delightful inheritance. He must provide salvation for them.
But he also perfectly loves his Father. This has two implications:
1. This salvation must be achieved justly. In other words, his Father’s honour which has been so sullied by the universal sin of humanity (Rom 3:10-20), must be upheld. God must be vindicated in his right and proper opposition to sin. So the salvation he will provide can’t be simply an overlooking of men’s sins, as that would dishonour God as the judge of all the earth. A way must be found to pay for men’s sins, justly.
2. Another way to think of this, however, is not in terms of sin and God’s justice – right and proper though that is. Think of love. Since the Father is love, exactly like the Son is love, in his love he too grieves for his lost and estranged image bearers. The Son sees his Father’s grief, and determines to remove its cause – the estrangement of a lost humanity. Since God is love (1 John 4:8,16), the Father is more glorified in the salvation of an image bearer, than in their damnation.
Somehow, Jesus’ perfect love of Father and neighbour must both be satisfied. Men’s sins must be removed so that fellowship is restored, increasing the Father’s happiness, and it must be done justly.
The cross is the only logical answer. Christ gave himself to death on the cross, so that both his loves – love for the Father, and for neighbour, could be satisfied at once. Men are restored to the eternal joys of fellowship with the Father, and the Son. The obstacle of God’s justice is removed, so that God can love them freely again, restoring God’s joy too, since he delights more to love than to judge.
Every other religion fails at this point. God cannot be both perfectly loving and perfectly just apart from the cross. If God merely overlooks sin, he violates his own justice. If God condemns eternally, he grieves his own love.
Furthermore, the cross can only be God’s own cross. The person bearing the judgement can be no innocent third party, punished for the sins of others, for that too would be unjust. Further, no merely finite being could atone for all the sins of all who would ever trust in Christ. If Jesus were a mere man, albeit perfect, perhaps it would be right for him to act as the substitute for just one other lucky person – but surely not more than one. How could the perfect life and sacrificial death of a mere man justly save more than one other? Only the infinite God could atone for multitudes hanging on a cross for 6 hours.
But it can only be a man who makes amends. A man caused the rupture, a man must restore it.
Therefore, logically, only a God-Man can do the job. And only his death will suffice. The perfect man, the God-Man, driven by love for Father and a lost humanity, determines to go to the cross for us.
Who would have thought that Jesus, the carpenter from Nazareth, was such a one. How surprising are God’s ways.