The "problem" that the idea of purgatory addresses is IMHO the effect of sin on the sinner. Sin is not just a matter if getting on God's bad side. It's not just a matter of justice, of what we owe God and one another.
It harms the self, and the harm is a moral harm. That is, it hurts the ability to do good and exacerbates the inability.
Experience indicates that those who have called upon the name of the Lord and are born again are rarely immediately and entirely free of the inclination to sin that they had before their conversion.
So it would SEEM that either what we do, and what kind of moral agents we are after our conversion is negligible or maybe our still tending to sin would indicate that while Gog has restored our relationship with God there is still some cleaning up to be done -- by someone, somehow - or we have the uncircumcised and unclean coming into the city where it was promised they would not/could not come. (Or, as I said earler, they wouldn't LIKE heaven. They'd hate it or would find it painful.)
Now I don't think that I need to change the gender of pronouns to find that kind of thing latent in Scripture.
How's that?
“How’s that?”
I’ll be gentle with you and say nothing.
And there, I believe, is the crux of the disagreement regarding the need for "purgatory". This "cleaning up" - when speaking of our remaining days as mortals after our conversion does indeed have very much to do with our Father's discipline, correction and chastisement and it is for our benefit, and those we have within our sphere of influence. It is to make us conformed to the image of Christ so that, through us, Christ is preached. Our way of life should be as a beacon drawing others to Christ and when we are disobedient and cause harm to the cause of Christ, we are dealt with as children of God. We are indwelled and sealed with "that Holy Spirit of promise".
But through it all, we are made righteous, we are sanctified, we HAVE BEEN justified by the grace of God through faith in the atonement of the blood of Christ. When we die - are taken home - we are not under condemnation - not for any part of the sins we have committed - we have passed from death unto life. That is the whole point of GRACE - undeserved mercy, undeserved love, undeserved pardon.
Heaven is indeed a place where there are only those that "are written in the Lamb's Book of Life", and we can only be there because of the finished work of our savior, Jesus Christ. All glory belongs to him!