Way before we were born. The predestined elect children of Jesus Christ will accept him as saviour because they can't do anything else.
Matthew 25:34"Then the King will say to those on His right, 'Come, you who are blessed of My Father, inherit the kingdom prepared for you from the foundation of the world."
"For many are called, but few [are] chosen." (Matthew 22:14, KJV)
"Before I formed you in the womb I knew you, before you were born I set you apart; I appointed you as a prophet to the nations." (Jeremiah 1:5 NIV)
"As soon as He was alone, His followers, along with the twelve, began asking Him about the parables. And He was saying to them, "To you has been given the mystery of the kingdom of God, but those who are outside get everything in parables, so that while seeing, they may see and not perceive, and while hearing, they may hear and not understand, otherwise they might return and be forgiven." (Mark 4:10-12, NASB)
"Blessed be the God and Father of our Lord Jesus Christ, who has blessed us with every spiritual blessing in the heavenly places in Christ, just as He chose us in Him before the foundation of the world, that we would be holy and blameless before Him. In love He predestined us to adoption as sons through Jesus Christ to Himself, according to the kind intention of His will,..." (Eph. 1:3-5, NASB)
"And we know that God causes all things to work together for good to those who love God, to those who are called according to His purpose. For those whom He foreknew, He also predestined to become conformed to the image of His Son, so that He would be the firstborn among many brethren; and these whom He predestined, He also called; and these whom He called, He also justified; and these whom He justified, He also glorified." (Rom. 8:28-30, NASB)
"... but we speak God's wisdom in a mystery, the hidden wisdom which God predestined before the ages to our glory; ..." (1Co. 2:7, NASB)
"For truly in this city there were gathered together against Your holy servant Jesus, whom You anointed, both Herod and Pontius Pilate, along with the Gentiles and the peoples of Israel, to do whatever Your hand and Your purpose predestined to occur." (Act. 4:27-28, NASB)
Your eyes have seen my unformed substance;And in Your book were all written The days that were ordained for me, When as yet there was not one of them. (Psa. 139:16, NASB)
"I will have mercy on whom I have mercy, and I will have compassion on whom I have compassion." It does not, therefore, depend on man's desire or effort, but on God's mercy. For the Scripture says to Pharaoh: "I raised you up for this very purpose, that I might display my power in you and that my name might be proclaimed in all the earth."Therefore God has mercy on whom he wants to have mercy, and he hardens whom he wants to harden." (Romans 9:15-18, NIV)
"The LORD said to Moses, "When you return to Egypt, see that you perform before Pharaoh all the wonders I have given you the power to do. But I will harden his heart so that he will not let the people go." (Exodus 4:21, NIV)
"What if God, choosing to show his wrath and make his power known, bore with great patience the objects of his wrath—prepared for destruction? What if he did this to make the riches of his glory known to the objects of his mercy, whom he prepared in advance for glory— even us, whom he also called, not only from the Jews but also from the Gentiles?" (Rom. 9:22-24, NIV)
"For by grace you have been saved through faith and that not of yourselves; it is the gift of God, not of works, lest anyone should boast. For we are His workmanship, created in Christ Jesus for good works, which God prepared beforehand that we should walk in them (Ephesians 2:8-10, NKJ)
"And when the Gentiles heard this, they began rejoicing and glorifying the word of the Lord, and as many as were appointed to eternal life believed." (Acts 13:48, ESV)