When Paul mentioned this to the Corinthian church:

II Corinthians 13:5 Examine yourselves, whether ye be in the faith; prove your own selves. Know ye not your own selves, how that Jesus Christ is in you, except ye be reprobates?

Was Paul hinting that a number weren't saved, and that they needed to find out, and then get saved?

If so, was he secretly excluding them, the 36 times he wrote, "brethren", in the two letters to the Corinthian church?

Was he also secretly excluding them when he wrote:

I Corinthians 1:8 Who shall also confirm you unto the end, that ye may be blameless in the day of our Lord Jesus Christ.

  9 God is faithful, by whom ye were called unto the fellowship of his Son Jesus Christ our Lord.

He wrote, "Examine yourselves, whether ye be in the faith".

But he didn't write, "whether you have faith", or "whether you believe".

Perhaps he's not asking them to check if they're really saved, because lost people generally won't do that.

The expression, "in the faith", is used other times:

Acts 14:22 Confirming the souls of the disciples, and exhorting them to continue in the faith, and that we must through much tribulation enter into the kingdom of God.

Where they exhorting them to, "stay saved"? Or were they exhorting them to continue as they were taught?

Acts 16:5 And so were the churches established in the faith, and increased in number daily.

Established in who they believe in, and what they believe.

Romans 14:1 Him that is weak in the faith receive ye, but not to doubtful disputations.

It's not saying that someone is only weakly saved, or barely saved.

I Corinthians 16:13 Watch ye, stand fast in the faith, quit you like men, be strong.

To stand by what they have been taught, what they believe in.

Colossians 1:23 If ye continue in the faith grounded and settled, and be not moved away from the hope of the gospel, which ye have heard, and which was preached to every creature which is under heaven; whereof I Paul am made a minister;

Again, he's not telling them to "continue being saved".

Also, when he wrote, "prove your own selves", to the Corinthian church, it doesn't seem that he is telling them to prove that they are saved.

However, the first two parts, examine and prove:

II Corinthians 13:5 Examine yourselves, whether ye be in the faith; prove your own selves. Know ye not your own selves, how that Jesus Christ is in you, except ye be reprobates?

Sounds a lot like:

Psalms 26:2 Examine me, O LORD, and prove me; try my reins and my heart.

Where David seems to be asking the LORD to see where his heart is at, not whether he believes or not.

Which is possibly a little how Paul wrote that for the Corinthian church.

Except, now, as Christians, they can, by the Spirit, examine themselves, and prove their own selves.

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