When the Gentiles heard this, they were glad and praised the word of the Lord; and as many as had been destined for eternal life became believers. Thus the word of the Lord spread throughout the region. Acts 13:48
Being destined for eternal life means what is presently done by the Lord. Apostle Paul does not say fore destined, or fore ordained, and is indicating the present work of the word of the Lord in the lives of those who respond to Christ. They’re saved! It is that which is happening at the very time that the people hear it. Thus, those who believe in Christ Jesus as Lord and Savior are destined to receive abundant life present and eternal life when they die.
God is the One who gives the power to believe. It is not you or I. God is giving you the ultimate gift in Christ which is the power to believe. This Scripture’s parallel is in Acts 16:14, where the original word does not designate predestination. God opens our hearts to believe in Jesus Christ and then praise. Some choose to go through the open Way to Christ and sadly, some thrust Him away. Salvation is offered through unmerited Grace of God.
And the word of the Lord spreads throughout the region because Paul and Barnabas are preaching, speaking the word of the Lord, and witnessing to the Lord’s activities in their personal lives. Others who come to Christ then share similarly. Yet in that region there are those opposed to the Lord’s calling and they stir up folks with power and position to publicly try and displace Paul and Barnabas. So the disciples go to Iconium, to return later, having shaken the dust off their feet.
And the disciples are filled with joy and with the Holy Spirit.