Okay, let's rehash the situation in which it was said. btw, it was just said again in the last few posts. i.e. your verses cannot mean what you say they mean because of what I think John 10:28 means to me.
In James 5:9 and in James 5:12, it is clearly written to believers, and both speak of possible condemnation. The response to these passages was that they cannot possibly mean what they say because if they did they would be contradicting what you think is the clear meaning of John 10:28.
But both of you are ignoring the fact that John 10:28 is a promise given to Jesus' sheep, whom Jesus knows, and that Jesus never knew those designated as workers of iniquity.
My take on it is that James is talking to people who think they are believers but may not truly be of God's elect. If they were God's elect there would be no possibility of condemnation, John 10:28 applies. But there are those who believe for a while and then fall away, these are not recipients of the promise of John 10:28, and may indeed fall into condemnation according to James 5:9 and James 5:12.
Here are the verses again:
James 5:9, Grudge not one against another, BRETHREN, LEST YE BE CONDEMNED: behold, the judge standeth at the door.
James 5:12, But above all things, MY BRETHREN, swear not, neither by heaven, neither by the earth, neither by any other oath: but let your yea be yea, and your nay, nay, LEST YE FALL INTO CONDEMNATION.
The answer was that condemnation doesn't really mean condemnation (i.e. hell and then the lake of fire) because you think John 10:28 trumps these verses. But again, John 10:28 is a promise given to Jesus' true sheep, or God's elect, or those who are saved from the perspective of eternity (not those who believe for a while and then fall away). Condemnation is possible for those who might be called BRETHREN, those who believe but for whom their faith will not last, it will not endure the test or trial of genuine faith (see 1 Peter 1:6-7).