1 John 2:1-2. 'My little children , these things I write to you so that you may not sin. And if anyone sins, we have an advocate with the Father, Jesus Christ the righteous.
And He Himself is the propitiation for our sins, and not for ours only but also for the whole world.'
I promised on another thread to post something on these verses, so here goes!
The first thing to note is that there is not much 'iffy' about 'if anyone sins.' In 1:10, John has told us that if we say we have not sinned we make God out to be a liar. He has told us elsehere that 'all [Jew and Gentile alike] have sinned and fall short of the glory of God. John's purpose in these early verses is to tell us that we should aim high - to seek to live a life that is worthy of such a gracious God and such a wonderful Saviour. But when we fall short, as we will, we should not despair, for we have an advocate in heaven, who intercedes with the Father on our behalf (Isaiah 53:12; Hebrews 7:25).
So what does the Lord Jesus plead on our behalf before the Father? Does He say, "Father, these men are innocent!" Hardly! Does He excuse our sin and plead extenuating circumstances? Does He plead our ignorance of the God's holiness or claim that we did not know what we were doing? No, we all have a conscience and know quite well when we do wrong.
So does He plead for those who have believed on Him? Yes, but that is not what is being said here. Remarkably, the word 'believe' does not occur in 1 John until 3:23, and 'faith' not until 5:4. If we want to know what our Lord pleads before the Father, we must look at verse 2. He is the propitiation for our sins. What is a propitiation? It is a sacrifice that turns away wrath. We read in Psalms 7:11 that God is angry with sinners every day. His wrath is not an emotional thing, it is the just reaction of a righteous and holy God to trespasses and sin. And if that wrath is not propitiated somehow, judgment must fall.
But in His mercy, God has found a way to marry His righteousness to His mercy (Psalms 85:10). On the cross, the Lord Jesus Christ became our surety or guarantor; He paid the penalty of the sins of a vast crowd of sinners, so many that no man can count them (Revelation 7:9-10), and turned away God's righteous anger from them. It is this that He pleads before the Father, saying perhaps, something like this: "Father, I have paid the price of these people's sin. The marks on my hands, feet and side testify that I have suffered in full the wrath and judgment that their sin deserved." Whether He uses such words as these, I have no idea, but there is no question of our Lord's intercession being unsuccessful. It was the Father who gave these people to the Son to redeem (John 6:39; 10:29 etc.) and in the light of His suffering, He will deny His beloved Son nothing which He asks for (Psalms 2:8; John 17:24).
So who or what is the 'whole world' in verse 2? It cannot be every single person in the world, because if Christ has propitiated the Father towards every single person and is interceding for them, then they will all be saved, which we know is not the case. Most Reformed commentaries see it as the elect, believers from every nation, tribe, people and tongue (Revelation 7:9 again). There is nothing wrong with this, but I have another theory, which I offer tentatively, that 'world' means Planet Earth.
In Genesis 3:17, God places a curse upon the 'ground' [Heb. 'adamah; also 'earth' or 'land') because of Man's sin. The curse appears again in Genesis 5:29, but chiefly in Romans 18-23. Here we learn that the creation was made subject to 'futility,' bondage and corruption by God, but that it will be delivered from these things at the end of time. In Revelation 22:3, we learn that in the new heaven and new earth there will be 'no more curse.' Why not? Because the blood of Christ, dropping from His tortured body, fell upon the earth and expiated the curse. So at the same time as our bodies are changed from corruption to incorrumption, so the world we shall live in shall also be changed, so that the perfected children of God may inhabit a perfect environment.
'Payment God will not twice demand;
Once at my bleeding Surety's hand,
And then again from me.' [Augustus Toplady]
I don't think there is any way you can say that Jesus died for the sins of a planet. The Planet earth has no sins. It is subject to the curse, but it cannot be redeemed. It does not have the faculty that allows is to make responsible choices.