While the text isn’t completely clear, it would seem as though there is the general concept of the co-operative roles at the final judgment of Jesus, as the font of mercy for us, preparing for God’s judgment. Peter states from Acts 3:19-21:
Be penitent, therefore, and be converted, that your sins may be blotted out. That when the times of refreshment shall come from the presence of the Lord, and he shall send him who hath been preached unto you, Jesus Christ, Whom heaven indeed must receive, until the times of the restitution of all things, which God hath spoken by the mouth of his holy prophets, from the beginning of the world.
Also Jude’s final doxology starting at v24:
Now to him who is able to preserve you without sin, and to present you spotless before the presence of his glory with exceeding joy, in the coming of our Lord Jesus Christ, To the only God our Saviour through Jesus Christ our Lord, be glory and magnificence, empire and power, before all ages, and now, and for all ages of ages. Amen.
So now, speaking of Onesiphorus (who may be dead at this point), Paul seems to be saying, “May the Lord (Father) grant him (Onesiphorus) to find mercy (for all of his good service) from the Lord (Jesus) on that day (his judgment)” [all green is my words.]
