For the Greek students out there!
When this scripture says "all sins" is there any indication in the original Greek of the "tense" it is referring to...is it indicating our passed and future sins are forgiven from the point of being "born again" or being made "alive in Christ" or just passed sins? Or is it even a relavant question?
The biggest problem here is the version you quote from.
Aside from that, there is one other word in the text that should make it clear. "Uncircumcision".
Especially in the NT, it is made very clear that the OT ritual of circumcision means nothing except to the Gnostic Jews. Which Paul explains well in Galatians.
"For in Jesus Christ neither circumcision availeth any thing, nor uncircumcision;" -Gal.5:6 (KJV)
But what does matter is circumcision of the heart.
"But he is a Jew, which is one inwardly; and circumcision is that of the heart, in the spirit, and not in the letter; whose praise is not of men, but of God." -Rom. 2:29 (KJV)
"You
were dead (past tense) in sins and in the uncircumcision of your heart" And now (present tense) are alive in
with Christ, and your sins (past tense) are forgiven.
Once you are saved, we are told that sins are cast into the sea of forgetfulness, as far as the east is from west. And should you sin, God made provisions for that also. (cf. 1 Jn. 1:8-10)
Now please understand, I'm not advocating antinomianism (lawlessness), that is what John wrote about in 1 Jn. 3:4,6,8-9, one simply cannot, I repeat, cannot sin as he/she pleases thinking its already been taken care of. That trods underfoot the Grace of God.
You must realize that nobody is, was, will be perfect in their lifetime. There was one and only One person who ever lived and lived sinlessly. And we are not Him!
We will stumble, we will fall. We will not be perfect until Jesus returns and we are made like Him. (cf. 1 Jn. 3:2)
God Bless
Till all are one.