What does scripture say about praying for the salvation of a particular individual? Is that a practice found in scripture?
Here are a few the come to mind off the top of my head....
Romans 10:1-4 - "Brothers, my heart's desire and prayer to God for them is that they may be saved. 2 For I bear them witness that they have a zeal for God, but not according to knowledge. 3 For, being ignorant of the righteousness of God, and seeking to establish their own, they did not submit to God's righteousness. 4 For Christ is the end of the law for righteousness to everyone who believes."
John 17 "... glorify your Son that the Son may glorify you, 2 since you have given him authority over all flesh, to give eternal life to all whom you have given him. 3 And this is eternal life, that they know you the only true God, and Jesus Christ whom you have sent...I am praying for them. I am not praying for the world but for those whom you have given me, for they are yours ... And for their sake I consecrate myself,[c] that they also may be sanctified[d] in truth....“I do not ask for these only, but also for those who will believe in me through their word, 21 that they may all be one, just as you, Father, are in me, and I in you, that they also may be in us, so that the world may believe that you have sent me...Father, I desire that they also, whom you have given me, may be with me where I am, to see my glory that you have given me because you loved me before the foundation of the world.
Isaiah 53:12 - And [Jesus] made intercession for the transgressors”
1 Timothy 2:1-6 - First of all, then, I urge that supplications, prayers, intercessions, and thanksgivings be made for all people, for kings and all who are in high positions, that we may lead a peaceful and quiet life, godly and dignified in every way. This is good, and it is pleasing in the sight of God our Savior, who desires all people to be saved and to come to the knowledge of the truth. For there is one God, and there is one mediator between God and men, the man Christ Jesus,
Matthew 9:37-38 - Then he said to his disciples, “The harvest is plentiful, but the laborers are few; therefore pray earnestly to the Lord of the harvest to send out laborers into his harvest.”
Praying for an individual's salvation only makes sense if God is sovereign over that person's salvation. There would be no need to pray for a person to be saved if God was not allowed to disarm man's hostile will and put in him a new heart that believes. Why? Because such a prayer would amount to nothing more than outward persuasion, something we can do ourselves. No, when we pray for a person's salvation we a praying that God overcome their innate hostility and soften their hardened heart. If God did not do this then no one would be saved. Left to our own will we wold all be lost.