World without end?
It is a common ending for a Catholic prayer.
For example,
Glory Be
Glory be to the Father,
and to the Son,
and to the Holy Spirit,
as it was in the beginning,
is now, and ever shall be,
world without end. Amen.
Grace After Meals
We give Thee thanks for all Thy benefits, O Almighty God, who
livest and reignest world without end. Amen. May the souls of the
faithful departed, through the mercy of God, rest in peace.
Amen.