Briefly, the argument that SOME do not go to purgatory is compatible with our belief. We do not hold that ALL need purgation after death.
But all have sinned and yes all still have committed sin after their moment of salvation. Who are the SOME then? That's not the way it works. You break one commandment the guilt is the same as breaking them all. We can't save ourselves. ANY punishments in this life or the next life can not pay the debt of sin nor remove one blot of it nor undo it's damage.
For that reason was John 3:16-18. By HIS Stripes we are healed by HIS sacrifice for our sins we are purchased and set free from all our sins for The Bible plainly says those whom the Son sets free are free indeed. Our sinful portion of our soul is no more as it is sealed by the Lambs Blood. The curse of this world is no more once we die if we die in Christ. We are new beings Born Again with a cleansed spirit and new bodies GOD intended us too have. We are healed from our sins in the same way as the ones with leprosy Christ healed or as the blind or lame he healed from their physical ailments. We are even as the one whom He cast the demons out of and the demons left the person and were cast in the sea.
Our sins are gone as is all the pains, hurts, and disappointments of this life at the second of our physical death IF we believe Christ died for our sins and accept His free gift of salvation. We are set free.
Not even Christ chosen disciples could live a perfect sin free life even after Christ ascended into heaven. These were ones whom had seen all the miracles yet there was still bickering and strong disagreements on some issues for some time too come. Yes even Simon Peter made some major mistakes in his judgment which Paul brought to his attention. Surely a man who denied Christ three times would have residual sins and damage? No he would not because Peter was under Grace.
The thing about sin is even though we receive our salvation over time with The Holy Spirit working within us our sin becomes more displeasing too us because The Holy Spirit at work in us is ministering to our souls. For some getting to that point takes longer then others. Others try to do The Holy Spirits work by self inflicting torments or punishmnets or worse allow other too do so on themselves as if that somehow will make it go away. The answer is a prayer away and can be prayed anywhere at anytime.
There is but one sin man can not be forgiven. It is the total deliberate and conscious rejection of Jesus Christ as Lord and Savior unto ones death. The Holy Spirit talks too the heart of all sinners to come too Christ. When is it too late? Only GOD knows for sure. It wasn't too late for the thief on the cross. But then again we know not the moment GOD gives us our last heart beat and breath.
But yet you take it upon yourselves to determine who went straight to heaven, obviously based on the outward appearance of the man/woman
1Sa 16:7 But the LORD said unto Samuel, Look not on his countenance, or on the height of his stature; because I have refused him: for the LORD seeth not as man seeth; for man looketh on the outward appearance, but the LORD looketh on the heart...