Was Jesus Plan B?

Saying Jesus is plan B would indicate that plan A was a failure. And in the story of the garden I really don't think that was the case. In the garden, God gave mankind (specifically Adam) a choice. And God had a plan for whichever path man chose. It may have been God's desire for man not make the choice he did, but for our sake he allowed it to happen.

Unlike Dan, I think there is a greater plan, as the prophecy in Gen 3:15 implies once man made his choice God put it into action:

And I will cause hostility between you and the woman, and between your offspring and her offspring. He will strike[b] your head, and you will strike his heel. (NLT)

As God knows everything from the beginning He can't have plan Bs for anything.

Years ago I used to answer this sort of question along the lines of God did not want robots to love him, so they had to have free will, etc. However this is not really an argument from the Bible itself. That kind of answer aims far to low to be Biblical. The Bible ascribed as things done for the praise of God's grace to the manifestation of that same grace, whereby we can all enjoy that same grace forever. The reason for everything, even though it seems things went wrong, is according to God's pleasure. This does not excuse the sinfulness of sin or Gods will that none should sin, it only admits God knew every sin that man would ever commit and planned to provide atonement by the death of His Son before the world was created. God does not live in time, so whatever happens tomorrow is no more distant than what happened before he fell.

Ephesians 1:3-6 is a typical verse declaring this truth, which has always been the position of great theologians:

3Praise be to the God and Father of our Lord Jesus Christ, who has blessed us in the heavenly realms with every spiritual blessing in Christ. 4For he chose us in him before the creation of the world to be holy and blameless in his sight. In love 5he c predestined us to be adopted as his sons through Jesus Christ, in accordance with his pleasure and will— 6to the praise of his glorious grace, which he has freely given us in the One he loves.

Notice everything was known 'before the creation' and that everything was done to the 'praise of his glorious grace'. Now I take these verses to mean that mankind's understanding and experience of God's grace, goodness and love, which can only lead us to praise and experience that grace, is at a 'higher realm' after the fall and salvation of mankind in Christ, then if there was no fall at all.

This is no plan B..

I found a quote by Martin Luther on the exact same question and he seems to have held the same view I propose:

If God should be asked at the last judgment, ‘Why did you permit Adam to fall?’ and he answered, ‘In order that my goodness toward the human race might be understood when I gave my Son for man’s salvation,’ we would say, ‘Let the whole human race fall again in order that thy glory may become known! Because thou hast accomplished so much through Adam’s fall we do not understand thy ways.’ “There is a threefold light: that of reason, that of grace, and that of glory.” (Luther's Works Volume 54, P385)

Martin Luther, Calvin, John Owen, Jonathan Edwards, etc. all held this view. Talking about God not wanting’ robots’ is rather silly by comparison. It's a man center view and fairly earthly.

Subject likes this must be resolved into God's own good pleasure and grace, we can only have faith like the Apostle:

Oh, the depth of the riches of the wisdom and knowledge of God! How unsearchable his judgments, and his paths beyond tracing out! “Who has known the mind of the Lord? Or who has been his counselor?” “Who has ever given to God, that God should repay them?” For from him and through him and for him are all things. To him be the glory forever! Amen. (Romans 11:33-36)