Larry: I don't understand why they have switched eternal to everlasting and vice versa.
It's good that you bring this up. I'm writing a book on the new translation, and I want to make sure I don't overlook issues such as this one.
(There is no change in the Apostles' Creed, where "life everlasting" is still translated as "life everlasting".)
The new translation does change ONE instances of "eternal" to "everlasting", and MANY instances "everlasting" to "eternal", in the prayers of the priest.
- In the absolution at the end of the Penitential Rite, the priest will no longer say "bring us to everlasting life" but "lead us ... into eternal life."
- In the Eucharistic Prayers, "everlasting covenant" will become "eternal covenant."
- In Eucharistic Prayer I, "the bread of life and the cup of eternal salvation" will become "the holy Bread of eternal life and the Chalice of everlasting salvation." (This is the only place where the new translation uses "everlasting" in the prayers of the priest.)
- In Eucharistic Prayer III, "make us an everlasting gift to you" will become "make of us an eternal offering to you."
- In Eucharistic Prayer IV, the phrase during the epiclesis "he left us as an everlasting covenant" will become "he left us as an eternal covenant."
- The priest's private prayers as he receives Communion will change from "everlasting life" to "eternal life."
Larry: It looks to me however like they just wanted to switch the wording around, because they switched it just about everywhere even where the present wording makes more sence.
The major driving force behind the new translation is greater fidelity to the Latin text of the Mass, respecting the richness of the Latin words and trying to reproduce that richness faithfully in the vernacular. Let me use one example from the above:
In Eucharistic Prayer I (the Roman Canon), the Latin text reads Panem sanctum vitae aeternae, et Calicem salutis perpetuae. In the current ("old") translation, this is "the bread of life and the cup of eternal salvation." The future ("new") translation will be "the holy Bread of eternal life and the Chalice of everlasting salvation." The new translation respects the vitae aeternae, rendering it as "eternal life" rather than just "life", and it respects the salutis perpetuae as "everlasting salvation" instead of "eternal salvation." This is for two reasons: first, the Latin uses two different words (aeternae and perpetuae), so the English translation should (unless there's a good reason) use two different English words ("eternal" for aeternae and "everlasting" for perpetuae, i.e. perpetual).
The word "eternal" is a direct translation (cognate) of aeternae, which is why the decision was made to use "eternal life" rather than "everlasting life" there. (Granted, in the Apostles' Creed, the phrase vitam aeternam is translated "life everlasting".) Because the words aeternae and perpetuae are used in immediate succession, it would not respect the Latin text to say "eternal life" and then "eternal salvation".
Now, I would posit that "everlasting life" is different from "eternal life". Everlasting life means life without end: both the saved and the damned will have everlasting life. But only the saved will experience eternal life, because the saved will share in the life of the Most Holy Trinity, God, Who lives eternally. Eternal life has neither beginning nor end, and when we come to share in the divine nature of God, we will share in His eternal life, not just the everlasting life which all souls will come to know.
So our salvation is not eternal salvation but everlasting, because we are not created saved, but become saved at some point in time.
If you would like, I can address the other changes too, but I think my explanations could be inferred from what I've said here about this one particular example (which uses both "eternal" and "everlasting").
Larry: I think they are changing too much at once...
There are people who said that (and are still saying that) about the changes in the 1960's. ;)
The changes that will be made are important and necessary (in my opinion and in the opinion of the Holy See). They've been in the works for nearly 10 years. It's less efficient (and more expensive) to make translation changes little by little, because that would mean new liturgical books would need to be issued and re-issued.