I don't know this person so maybe they were speaking for themselves, but I have never found any indication in Gods word about we as Believers being sinners. As a matter of fact this statement is in contradiction to what the bible actually says about us as believers. The bible says we are ambassadors of Christ, his representatives on earth. How can a sinner represent a holy, sinless God that cannot even look on sin. We are citizens of heaven, Through the Blood we have been made the righteousness of God through Christ, The one who was without sin was made sin for us. He took our sins and made us Righteous (in right standing with God). So if we are sinners He really did not take our sin and we are not righteous. We are not citizens of heaven, or ambassadors of Christ. So where does that leave us.
John says in his 1st epistle that we do sin but if we confess He is faithful to forgive us our sins and cleanse us from ALL unrighteousness. He later goes on to say that whoever abides in Him does not sin. What he is saying is that even though we sin we are not sinners because that sin cannot live in us since Holy Spirit lives in us and the 2 cannot live together. As believers we are not characterized by sin. It is not natural to the believer. When we do commit a sin Holy Spirit, that lives in us, convicts us of that sin, we repent and He is faithful to forgive us. Children of God cannot sin without the Spirits conviction. Living constantly, I believe, in sin goes against the claim of having a relationship with God through Christ.If we are to conclude that we are sinners, then how can we be holy, when in Hebrews 12:14 Paul says pursue holiness, without which no one will see The Lord.
Eat the Bread, Drink the Wine. How He loves Us!!