Some years back, I composed this prayer for use in Advent, especially when reading the prophet Isaias; I've just had a go at translating it into God's own Latin, but could do with some advice on how to do so better – please advise:
O God, who by Isaias thy prophet hast revealed unto thy servants the mysteries of the first advent of thine only-begotten Son in humility to save us by his incarnation, passion and resurrection, and of his second advent in glory to judge the living and the dead and the world by fire: grant us grace so to unite ourselves by faith and good works to the humble Christ, that the glorious Christ may number us among the chosen of his kingdom; who liveth and reigneth world without end. Amen.
Deus, qui per Isaiam prophetam tuam revelasti famulis tuis mysteria primi adventus unigeniti Filii tui in humilitatem ad salvandum nos per incarnationem, passionem et resurrectionem suam, et secundi adventus sui in gloria ad judicandos vivos et mortuos, et sæculum per ignem: da nobis gratiam ita unire nosmetipsos fide et bonis operibus Christo humili, ut Christus gloriosus annumeraret nos inter electos regni sui; qui vivit et regnat in sæcula sæculorum. Amen.