Why, of course the tense matters. What I am saying is that boh past and present tense in employed, but when the present tense is employed it is not clear from the Greek (or English) if it is continuous mood ("you are being saved") or past perfect ("you have been saved"). English has grammatical categories that patristic Greek doesn't have, so the translator ends up with non-specific "you are saved".
I know what you are saying annalex, which is why you said it not as simple as tense. But it is. The Church never confused which tense it was understood to be -- the future. Because when we are saved we are purified and spotless, immaculate if you will, worthy of being heaven, sainted, healed. In either case it is the end of a process of healing, purification, of perfecting.
Take for instance the famous verse "Be therefore perfect as your Father in heaven is perfect." What does that mean? In Greek it is in the future -- "will be" or become -- therefore perfect...