St. Irenaeus asked that God strengthen them and show them the truth, keeping them from every error.
St. Irenaeus was an influential bishop of the 2nd century and did much to combat heresy, clearly defining true Christian doctrine.
Not only did he write about such truth, he also prayed for his readers, that they would find the truth in Jesus Christ.
Here is a short prayer from Against Heresies that asks God to protect those seeking the truth from every false doctrine.
Wherefore I do also call upon you, Lord God of Abraham, and God of Isaac, and God of Jacob and Israel, who is the Father of our Lord Jesus Christ, the God who, through the abundance of Your mercy, has had a favor towards us, that we should know You, who has made heaven and earth, who rule over all, who is the only and the true God, above whom there is none other God; grant, by our Lord Jesus Christ, the governing power of the Holy Spirit; give to every reader of this book to know You, that You are God alone, to be strengthened in You, and to avoid every heretical, and godless, and impious doctrine.