Not as though I had already. attained, either were already perfect; the R.V. renders this clause more accurately, not that (I do not say that) I have already obtained. The verb is not the same with that translated "attain" in Philippians 3:11; it means to get, to win a prize, as in 1 Corinthians 9:24.
The tense is aorist: "I say not that I did at once win the prize;" that is, at the time of his conversion. Compare the tenses used in 1 Corinthians 9:8, "I suffered the loss of all things;" and 1 Corinthians 9:12, "I was apprehended;" which both refer to the same time.
The prize was gained in a moment; it needs the continued effort of a lifetime. St. Paul proceeds, using now the perfect tense, "Nor have I been already made perfect." He has not even now reached perfection; he is still working out his own salvation.
There may be here a delicate allusion to the spiritual pride which seems to have disturbed the unity of the Philippians (see Philippians 2:2-4). But I follow after; rather, I pursue, I press on. If that I may apprehend that for which also I am apprehended of Christ Jesus.