God's plan is not an afterthought. His plan is well calculated and was formed before the need arose.

“All who dwell on the earth will worship him, whose names have not been written in the Book of Life of the Lamb slain from the foundation of the world.” Revelation 13:8

“just as He chose us in Him before the foundation of the world, that we should be holy and without blame before Him in love, having predestined us to adoption as sons by Jesus Christ to Himself, according to the good pleasure of His will.” Ephesians 1:4-5

“He indeed was foreordained before the foundation of the world, but was manifest in these last times for you.” 1 Peter 1:20

“who has saved us and called us with a holy calling, not according to our works, but according to His own purpose and grace which was given to us in Christ Jesus before time began” 2 Timothy 1:9

God and Christ knew from the beginning, of the apostasy of Satan and of the fall of Adam through the deceptive power of the apostate. The plan of salvation was designed to redeem the fallen race, to give them another trial. Christ was appointed to the office of Mediator from the creation of God, set up from everlasting to be our substitute and surety. Before the world was made, it was arranged that the divinity of Christ should be enshrouded in humanity. 1SM 250.1

All the inhabitants of the earth are reputed as nothing; He does according to His will in the army of heaven And among the inhabitants of the earth. No one can restrain His hand Or say to Him, “What have You done?” Daniel 4:35

“I know that You can do everything, And that no purpose of Yours can be withheld from You.” Job 42:2

Remember the former things of old, For I am God, and there is no other; I am God, and there is none like Me, Declaring the end from the beginning, And from ancient times things that are not yet done, Saying, 'My counsel shall stand, And I will do all My pleasure,' Isaiah 46:9-10

To Adam and Eve, God revealed a bit of His mission plan.

“And I will put enmity Between you and the woman, And between your seed and her Seed; He shall bruise your head, And you shall bruise His heel.” Genesis 3:15

To Abraham, God said,

“I will bless those who bless you, and I will curse him who curses you; and in you all the families of the earth shall be blessed.” Genesis 12:3

And the Scripture, foreseeing that God would justify the Gentiles by faith, preached the gospel to Abraham beforehand, saying, “In you all the nations shall be blessed.” Galatians 3:8

Israel existed to be a missionary nation.

Now therefore, if you will indeed obey My voice and keep My covenant, then you shall be a special treasure to Me above all people; for all the earth is Mine. And you shall be to Me a kingdom of priests and a holy nation.' These are the words which you shall speak to the children of Israel.“ Exodus 19:5-6

Indeed He says, 'It is too small a thing that You should be My Servant To raise up the tribes of Jacob, And to restore the preserved ones of Israel; I will also give You as a light to the Gentiles, That You should be My salvation to the ends of the earth.' ” Isaiah 49:6

Jesus fulfilled His mission

God, who at various times and in various ways spoke in time past to the fathers by the prophets, has in these last days spoken to us by His Son, whom He has appointed heir of all things, through whom also He made the worlds; Hebrews 1:1-2

“for the Son of Man has come to seek and to save that which was lost.” Luke 19:10

And beginning at Moses and all the Prophets, He expounded to them in all the Scriptures the things concerning Himself. Luke 24:27

And we declare to you glad tidings–that promise which was made to the fathers. God has fulfilled this for us their children, in that He has raised up Jesus. As it is also written in the second Psalm: 'You are My Son, Today I have begotten You.' Acts 13:32-33

and to make all see what is the fellowship of the mystery, which from the beginning of the ages has been hidden in God who created all things through Jesus Christ; to the intent that now the manifold wisdom of God might be made known by the church to the principalities and powers in the heavenly places, according to the eternal purpose which He accomplished in Christ Jesus our Lord, Ephesians 3:9-11

God is already at work. We do not need to invent something. We need only to open our eyes, see where God is working, and join Him in His work.

“So Jesus said to them again, “Peace to you! As the Father has sent Me, I also send you.” John 20:21

As Jesus was sent from the Father, so Jesus sends us on His mission, to seek and to save that which was lost.