"And He Himself is the propitiation for our sins, and not ours only but also for the sins of the whole world."
- 1 John 2:2
The word propitiation in the Greek means to appease or satisfy. So, when the text says that He (Christ) is the propitiation for ours sins it means that Jesus satisfied God The Father's wrath for our trespasses when He sacrificed Himself for the sins of the world. Jesus' death for our sins was a complete and sufficient atonement for God. As a result, the Father extends His grace to all of mankind - commanding all to repent of their sins and trust in what Jesus did for them, suffering and dying in their place. When a person does this, they are forgiven of their sins and they receive the gift of eternal life. The Father pardons their sins and treats them as if they had never sinned. Amazing!
It is important that I make a critical distinction here. Just because Jesus died for the sins of the whole world, does not mean that everyone goes to heaven. Jesus had to die or else all of mankind is doomed to hell in a godless eternity. Jesus' death was/is completely sufficient to save every person that will ever live. But His death is only efficient (e.g. effective) to those who believe; meaning the benefits of Christ's atonement only applies savingly to the genuine repentant sinner. Those who refuse to believe do not receive the benefits God's saving grace because they willfully reject The Father's gift of eternal life in Christ alone. They by their own sinful rebellion have reserved themselves to the wrath of God (John 3:36). The wages of sin is death (Romans 6:23).
Rejection of Jesus Christ is suicide
When a person thinks they are secure in their soul despite their sin, they are deceived. That false security gives birth to defiance and arrogance which leads to a demonic narcissism. The tragic part about this is the person doesn't know that they are this way. They have made the determination that they do not need to receive the gospel and repent of their sins. They have determined for themselves that they are good. In Proverbs 14:12 we read, "There is a way that seems right to a man, but the end thereof are the ways of death." King Solomon the writer could not have said it more clearer than that. Man's way is the way to hell.
Charles Spurgeon on 1 John 2:2
By which is meant, not only that Jesus Christ died for Gentiles as well as Jews, and for some of all nations, but that there is that in the atonement of Christ which might be sufficient for every creature under heaven if God had so chosen every creature. The limitation lies, not in the value of the atonement itself, but in the design and intention of the Eternal God. God sent His Son to lay down His life for His sheep. We know that Christ redeemed us from among men, so that the redemption is particularly and specially for the elect; yet at the same time the price offered was so precious, the blood was so infinite in value, that if every man that ever lived had to be redeemed Christ could have done it. It is this that makes us bold to preach the gospel to every creature, since we know there is no limit in the value of the atonement, though still we know that the design of it is for the chosen people of God alone.
Charles Spurgeon, Spurgeon Commentary: 1 John, ed. Elliot Ritzema, Spurgeon Commentary Series (Bellingham, WA: Lexham Press, 2014), 1 Jn 2:2.
Matthew Henry
He
is the expiatory victim, the propitiatory sacrifice that has been offered to
the Judge for all our offences against his majesty, law, and government. In
vain do the professors of Rome distinguish between and advocate of redemption
and an advocate of intercession, or a mediator of such different service. The
Mediator of intercession, the Advocate for us, is the Mediator of redemption,
the propitiation for our sins. It is his propitiation that he pleads. And we
might be apt to suppose that his blood had lost its value and efficacy if no
mention had been made of it in heaven since the time it was shed. But now we
see it is of esteem there, since it is continually represented in the
intercession of the great advocate (the attorney-general) for the church of
God. He ever lives to make intercession for those that come to God through him.
4. By the extent of his plea, the latitude of his propitiation. It is not
confined to one nation; and not particularly to the ancient Israel of God: He
is the propitiation for our sins; and not for ours only (not only for the sins
of us Jews, us that are Abraham’s seed according to the flesh), but also for those
of the whole world (v. 2); not only for the past, or us present believers, but
for the sins of all who shall hereafter believe on him or come to God through
him. The extent and intent of the Mediator’s death reach to all tribes,
nations, and countries. As he is the only, so he is the universal atonement and
propitiation for all that are saved and brought home to God, and to his favor
and forgiveness.
Matthew Henry, Matthew Henry’s Commentary on the Whole Bible: Complete and Unabridged in One Volume (Peabody: Hendrickson, 1994), 2444.