Then no-one is saved because there's not a just man upon earth that doeth good and sinneth not.
Well, here is what
Ecclesiastes 7:20 says in the Good News Translation:
Ecclesiastes 7:20 GNT
"There is no one on earth who does what is right all the time and never makes a mistake."
In other words, this is speaking of the fact that a believer may do things that would not be classified as a sin that leads unto death (i.e. the Second Death or the Lake of Fire). Mistakes would fall under the category of hidden or secret faults as mentioned in Psalms 19:12. For there is a sin not unto death (1 John 5:16-17). An example of a sin not unto death is when Paul disobeyed the Spirit and went to Jerusalem. He was not condemned by this disobedience because his motivation in going to Jerusalem was to see the Jews in being saved. This is not talking about serious sins that lead unto spiritual death like lying, hating, stealing, murdering, fornicating, and getting drunk, etc.
Also, Ecclesiastes 7:20 was written during the time of the Old Testament, too (See
Hebrews 11:40).
You said:
If we say that we have no sin we deceive ourselves and the truth is not in us.
What is helpful in understanding 1 John 1:8 is looking at its immediate context. 1 John 1:10 says if we say we have not sinned. 1 John 1:10 switches gears from 1 John 1:8 in regards to time; John talks about the declaration on committing sin in verse 8 (which is present tense) to a declaration on committing sin being a past declaration (with verse 10). Verse 10 is saying there are people who said they have not sinned (past tense). This is clearly a gnostic belief. Why? Well, most believers today hold to the idea that they have sinned as a part of their old life before coming to Christ (Regardless of whether they are “OSAS,” a “Sin and still be saved” type believer, or a “Conditional Salvationist”). So this clearly is a “gnostic belief” that John was warning the brethren about (See 1 John 2:26). 1 John 1:8 is a present declaration of sin. It is saying if we say we have no sin when we do sin (present tense). This has to be the interpretative understanding of this verse because 1 John 2:4 says if we say we know Him and do not keep His commandments we are a liar and the truth is not in us. The OSAS's interpretation on 1 John 1:8 does not work because it conflicts with a normal reading on 1 John 2:3-4. You cannot always be in sin (breaking God's commands) as a part of 1 John 1:8 and yet also fulfill 1 John 2:3 that says we can have an assurance of knowing Him if we keep His commandments. Especially when 1 John 2:4 says we are a liar and the truth is not in us if we break his commandments. In other words, if the OSAS interpretation on 1 John 1:8 was true, then I would be damned if I do by obeying God's commands (1 John 1:8) and yet I would be damned if I don't by not obeying God's commands (1 John 2:4).
In fact, the New English Translation says this for 1 John 1:8,
"If we say we do not bear the guilt of sin, we are deceiving ourselves and the truth is not in us." (1 John 1:8 NET).
In other words, this verse is saying that if a person sins and says they do not bear the guilt of sin (in the sense that they will not have to face any wrath or Judgment from God over their sin) then they would be deceiving themselves and the truth would not be in them. This is exactly what the Eternal Security proposes. They are saying that they do not bear the guilt of any sin (destruction of their soul and body in hell fire) if they do sin because they believe their future sins are paid for by Jesus. They are saying, they do not bear the guilt or the punishment of sin at the final Judgment because of their belief on Jesus. In short, 1 John 1:8 is a denial of the existence of sin on some level. “If we say we have no sin (in the sense that it does not exist) we deceive ourselves and the truth is not in us.” (1 John 1:8). Christian Scientists think sin is an illusion and does not exist at all. So this verse would apply to them. Eternal Security Proponents and those who deny that “Sin Can Separate a Believer from God” deny the existence of sin partially. They believe sin exists physically but they do not believe sin exists for them on a spiritual level because Jesus has forgiven them of all their sin by their belief on Jesus. In fact, to see just how silly your argument actually is for 1 John 1:8, you would have to believe that you are sinning right now at this very moment in order for such a verse to be true because 1 John 1:8 is speaking in the present tense.
John prescribes that we do not think that sin is an illusion, and we are automatically saved, but John is telling us to "sin not" and go to our advocate Jesus Christ (1 John 2:1), and confess our sins so as to be forgiven of sin and to be cleansed of all unrighteousness (1 John 1:9). How can you confess and be forgiven of sin if all your future sin is paid for? It makes no sense.
You can say that John is talking about a break of fellowship by one's sins and not a loss of salvation, but that would not be consistent with Scripture. 1 John 5:12 says he that has the Son has life, and he that does not have the Son does not have life.
You said:
No-one can keep His commandments.
Not true. For it is written,
5 “There was in the days of Herod, the king of Judaea, a certain priest named Zacharias, of the course of Abia: and his wife
was of the daughters of Aaron, and her name
was Elisabeth.
6 And
they were both righteous before God, walking in all the commandments and ordinances of the Lord blameless.” (Luke 1:5-6).
Revelation 22:14-15 says, “Blessed are they that do his commandments, that they may have right to the tree of life, and may enter in through the gates into the city. For without are dogs, and sorcerers, and whoremongers, and murderers, and idolaters, and whosoever loveth and maketh a lie.”