Ac 13:48 Now when the Gentiles heard this, they were glad and glorified the word of the Lord. And as many as had been appointed to eternal life believed.
First of all, the text does not say that God appointed them to eternal life in eternity past. No, this was done here in time.
Second, the Greek word for "appointed" here in the expression "As many as had been appointed to eternal life believed" can also be translated as disposed.
It can be translated as "as many as had been disposed to eternal life believed."
God is the one who inclines a sinner towards eternal life. Without this work, nobody is able to do so. God wants all to be saved. And so He works in all to dispose them to eternal life.
However, in His sovereignty, He decided to give a sinner a free choice. He frees up the will of a sinner. He inclines him towards eternal life, and if the sinner will not resist, He will, by God's grace, trust in Christ for it.
In this instance, the sinners who were drawn by God did not resist God's drawing. The result? As many as had been disposed to eternal life believed.
An example of this is Cornelius. Cornelius was a man disposed God to eternal life by God. He was a repentant man by the grace of God. And so God commanded him to send for Peter who will tell him words that he might be saved. Notice God's appointment of Cornelius for eternal life by setting him up to meet with His messenger, the apostle Peter.
Ac 10:30 So Cornelius said, "Four days ago I was fasting until this hour; and at the ninth hour I prayed in my house, and behold, a man stood before me in bright clothing,
31 "and said, 'Cornelius, your prayer has been heard, and your alms are remembered in the sight of God.
32 'Send therefore to Joppa and call Simon here, whose surname is Peter. He is lodging in the house of Simon, a tanner, by the sea. When he comes, he will speak to you.'
33 "So I sent to you immediately, and you have done well to come. Now therefore, we are all present before God, to hear all the things commanded you by God."
