My condolences on you and your friend’s loss.
Psalm 23 (The Lord is my shepherd) is a very good choice.
Ps. 27:1, 4-9, 13-14 (selected verses only). Ps. 4; Ps. 130.
Romans 8:31-35, 38-39:
What then shall we say to this? If God is for us, who is against us? He who did not spare his own Son but gave him up for us all, will he not also give us all things with him? Who shall bring any charge against God’s elect? It is God who justifies; who is to condemn? Is it Christ Jesus, who died, yes, who was raised from the dead, who is at the right hand of God, who indeed intercedes for us? Who shall separate us from the love of Christ? Shall tribulation, or distress, or persecution, or famine, or nakedness, or peril, or sword? For I am sure that neither death, nor life, nor angels, nor principalities, nor things present, nor things to come, nor powers, nor height, nor depth, nor anything else in all creation, will be able to separate us from the love of God in Christ Jesus our Lord. (Rom. 8:31-35, 38-39, RSV)
A few NT passages which are a little stronger but deal directly with the subject:
But in fact Christ has been raised from the dead, the first fruits of those who have fallen asleep. For as by a man came death, by a man has come also the resurrection of the dead. For as in Adam all die, so also in Christ shall all be made alive. But each in his own order: Christ the first fruits, then at his coming those who belong to Christ. Then comes the end, when he delivers the kingdom to God the Father after destroying every rule and every authority and power. For he must reign until he has put all his enemies under his feet. The last enemy to be destroyed is death. “For God has put all things in subjection under his feet.” But when it says, “All things are put in subjection under him,” it is plain that he is excepted who put all things under him. When all things are subjected to him, then the Son himself will also be subjected to him who put all things under him, that God may be everything to every one. (1 Cor. 15:20-28, RSV)
But we would not have you ignorant, brethren, concerning those who are asleep, that you may not grieve as others do who have no hope. For since we believe that Jesus died and rose again, even so, through Jesus, God will bring with him those who have fallen asleep. For this we declare to you by the word of the Lord, that we who are alive, who are left until the coming of the Lord, shall not precede those who have fallen asleep. For the Lord himself will descend from heaven with a cry of command, with the archangel’s call, and with the sound of the trumpet of God. And the dead in Christ will rise first; then we who are alive, who are left, shall be caught up together with them in the clouds to meet the Lord in the air; and so we shall always be with the Lord. Therefore comfort one another with these words. (1 Thess. 4:13-18, RSV)
Then I saw a new heaven and a new earth; for the first heaven and the first earth had passed away, and the sea was no more. And I saw the holy city, new Jerusalem, coming down out of heaven from God, prepared as a bride adorned for her husband; and I heard a loud voice from the throne saying, “Behold, the dwelling of God is with men. He will dwell with them, and they shall be his people, and God himself will be with them; he will wipe away every tear from their eyes, and death shall be no more, neither shall there be mourning nor crying nor pain any more, for the former things have passed away.” (Rev. 21:1-4, RSV)
There are other passages, but IMO these are some of the best. I hope you find something appropriate.
(N.B.: I’ve quoted from the RSV as I find the older versions more poetic than the newer translations, but the priest will probably choose his own version.)