Let's begin by understanding the Greek perfect tense.
From: http://www.biblestudymanuals.net/new_testament_greek.htm
"The perfect tense expresses perfective action. Perfective action involves a present state which has resulted from a past action. The present state is a continuing state; the past action is a completed action."
From: http://www.ntgreek.org/learn_nt_greek/inter-tense.htm
"The perfect tense has to do with the completed progress of an action and its corresponding finished results. That is, it shows a present state of affairs (from the writer’s perspective), based upon an action in past time (when using the indicative mood)."
So, to summarize from these websites, the perfect tense is about completed action with on-going results.
Now, let's consider this verse:
Eph 2:8
For it is by grace you have been saved, through faith — and this not from yourselves, it is the gift of God—
Here is the breakdown from www.biblestudymanuals.net -
"you have been saved.." = "este sesosmenoi..."
"este" = "are", 2 pers. pl. pres., active voice, indicative mood = statement of fact
"sesosmenoi" = saved, participle, perfect tense passive voice.
So, the phrase "have been saved" is a perfect tense indicative mood statement.
So, the completed action here is that one is saved as a completed action that has on-going results.
Therefore, the on-going results speaks to the fact that once saved in the perfect tense, the on-going results is that one stays saved.
The passive voice speaks to the fact that the action of salvation is not from oneself, or one's own believing, but, as www.ntgreek.org says: Passive Voice
Grammatical voice indicates whether the subject is the performer of the action of the verb (active voice), or the subject is the recipient of the action (passive voice). If the subject of the sentence is being acted upon, then the verb is referred to as being in the passive voice.
Therefore, Eph 2:8 is statement of fact, that we have been saved by faith (past action) with on-going results, meaning we stay saved.
From: http://www.biblestudymanuals.net/new_testament_greek.htm
"The perfect tense expresses perfective action. Perfective action involves a present state which has resulted from a past action. The present state is a continuing state; the past action is a completed action."
From: http://www.ntgreek.org/learn_nt_greek/inter-tense.htm
"The perfect tense has to do with the completed progress of an action and its corresponding finished results. That is, it shows a present state of affairs (from the writer’s perspective), based upon an action in past time (when using the indicative mood)."
So, to summarize from these websites, the perfect tense is about completed action with on-going results.
Now, let's consider this verse:
Eph 2:8
For it is by grace you have been saved, through faith — and this not from yourselves, it is the gift of God—
Here is the breakdown from www.biblestudymanuals.net -
"you have been saved.." = "este sesosmenoi..."
"este" = "are", 2 pers. pl. pres., active voice, indicative mood = statement of fact
"sesosmenoi" = saved, participle, perfect tense passive voice.
So, the phrase "have been saved" is a perfect tense indicative mood statement.
So, the completed action here is that one is saved as a completed action that has on-going results.
Therefore, the on-going results speaks to the fact that once saved in the perfect tense, the on-going results is that one stays saved.
The passive voice speaks to the fact that the action of salvation is not from oneself, or one's own believing, but, as www.ntgreek.org says: Passive Voice
Grammatical voice indicates whether the subject is the performer of the action of the verb (active voice), or the subject is the recipient of the action (passive voice). If the subject of the sentence is being acted upon, then the verb is referred to as being in the passive voice.
Therefore, Eph 2:8 is statement of fact, that we have been saved by faith (past action) with on-going results, meaning we stay saved.