Question on the order of Decrees - Lapsarianism

I got this email from one of my younger (but sharp!) brothers in the faith

Shorter Catechism Question 13:

Q. Did our first parents continue in the estate wherein they were created?

A. Our first parents, being left to the freedom of their own will, fell from the estate wherein they were created, by sinning against God.

As we all know, Adam and Eve were not in bondage to sin yet still capable of sinning. The triune God had ordained from eternity past that the Son would be redeemer of a fallen people, implying that God knew they would sin against Him. Could the case be made that God, in his foreknowledge of the fall, designated the Son as redeemer rather than God ordaining the fall. I know a good Calvinist doesn't accept this parallel in regards to salvation (the "corridors of time" fallacy used to dodge Romans 9 which contradicts verse 11.) But with lapsarianism, we're not dealing with merits of salvation but merely the question of whether or not God's ordainment was reactionary to the first humans or not. I suppose I'm flirting with Infralapsarianism. Give me some of your thoughts on the matter. Can this question not be solved by solely invoking God's foreknowledge? It seems like to go beyond mere foreknowledge would mean Adam and Eve had no choice but to sin which is the consequence of the fallen state. If they truly were able to sin AND able not to sin (as St. Augustine wrote), how could God have any involvement beyond looking down the corridors of time?

Here is my response to him.

Let's see if I can lay this out in a way that Christ is honored and confusion avoided:

Pre-Fall Man was ABLE not to sin, but not INCLINED - they were INCLINED to sin over obedience - out of their own self-generated pride - all God did was actualize the events that would lead to the Fall being realized for His good purpose.

Remember, foreknowledge is about fully knowing a person or events prior to actualization - that is, predestination.

The order of decrees logically necessitate the activities that follow.

Decree 1) In eternity past,the Godhead enters into covenant to be glorified through the Son as the Redeemer and Judge of a created people. Not to give God something He needed, but to give opportunity for others to commune with Him - out of His own good pleasure.

Acts 2:23
this Jesus, delivered up according to the definite plan and foreknowledge of God, you crucified and killed by the hands of lawless men.

John 5:22
The Father judges no one, but has given all judgment to the Son,

Decree 2) God plans the creation from alpha to omega with the Savior Son as the center and purpose of creation and Mankind decreed as the vessels of His purpose.

John 1:2-4 (English Standard Version)

²He was in the beginning with God. ³ All things were made through him, and without him was not any thing made that was made. ⁴ In him was life, and the life was the light of men.

Revelation 21:6-7 (English Standard Version)

⁶And he (Jesus) said to me, "It is done! I am the Alpha and the Omega, the beginning and the end. To the thirsty I will give from the spring of the water of life without payment. ⁷ The one who conquers will have this heritage, and I will be his God and he will be my son.

Romans 9:21-23 (English Standard Version)

²¹ Has the potter no right over the clay, to make out of the same lump one vessel for honorable use and another for dishonorable use? ²²What if God, desiring to show his wrath and to make known his power, has endured with much patience vessels of wrath prepared for destruction, ²³in order to make known the riches of his glory for vessels of mercy, which he has prepared beforehand for glory

Remember, we don't care about "What if's" -only "What is". Christ as Redeemer of Man necessitates the Fall, but does not necessitate sin be generated by the Father, as Man was able or not able to sin as a moral agent, however it was not POSSIBLE for Man not to sin.

In other words, Man had the ABILITY to sin or not to sin, but no PROBABILITY under God's sovereign plan that they would not - that is, while the ability existed, there was no confluence of events that would ever be that Man did not - all things worked together (were actualized) so that it WOULD NOT be. Man was not a slave to sin, but loved it over obedience, so it became his master - as God foreknew that Man would be - in order that the Son might glorify Him and His people and judge those that are not.

That is why even the Fall was a good and necessary consequence of God's plan. Romans 8:28

Thus, there is only one theologically tenable lapsarian position - supra :)