Definition #2 of Atonement from Websters dictionary.
2: the reconciliation of God and mankind through the sacrificial death of Jesus Christ.
Atonement by definition can only apply to the elect.
For I delivered to you first of all that which I also received: that Christ died for our sins according to the Scriptures, and that He was buried, and that He rose again the third day according to the Scriptures, and that He was seen by Cephas, then by the twelve.
Grace to you and peace from God the Father and our Lord Jesus Christ, who gave Himself for our sins, that He might deliver us from this present evil age, according to the will of our God and Father, to whom be glory forever and ever. Amen.
who being the brightness of His glory and the express image of His person, and upholding all things by the word of His power, when He had by Himself purged our sins, sat down at the right hand of the Majesty on high,
who Himself bore our sins in His own body on the tree, that we, having died to sins, might live for righteousness-by whose stripes you were healed.
In this is love, not that we loved God, but that He loved us and sent His Son to be the propitiation for our sins.
and from Jesus Christ, the faithful witness, the firstborn from the dead, and the ruler over the kings of the earth. To Him who loved us and washed us from our sins in His own blood, and has made us kings and priests to His God and Father, to Him be glory and dominion forever and ever. Amen.
Therefore take heed to yourselves and to all the flock, among which the Holy Spirit has made you overseers, to shepherd the church of God which He purchased with His own blood.
In Him you also trusted, after you heard the word of truth, the gospel of your salvation; in whom also, having believed, you were sealed with the Holy Spirit of promise, who is the guarantee of our inheritance until the redemption of the purchased possession, to the praise of His glory.
The following passage from 1 John is often used inappropriately, as evidence that Jesus died for everyone. But read the next passage from Revelation and you will see what he means by the whole world... not everyone, but the elect from every tongue, tribe, people and nation.
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.
And they sang a new song, saying: "You are worthy to take the scroll, and to open its seals; for You were slain, and have redeemed us to God by Your blood out of every tribe and tongue and people and nation, and have made us kings and priests to our God; and we shall reign on the earth."
And she will bring forth a Son, and you shall call His name JESUS, for He will save His people from their sins.
Now this he did not say on his own authority; but being high priest that year he prophesied that Jesus would die for the nation, and not for that nation only, but also that He would gather together in one the children of God who were scattered abroad.
Bib, believe the bible, not your man made definitions.