If Christ propitiated the sins of the whole world; if Christ paid for all the sins of the whole world at the cross, if unbelief is a sin, then you are preaching universalism. God would be unjust if Christ paid for the sins of the entire world, and later punish the unbeliever in Hell for the same sins Christ already paid for.
False logic. First off, Christ paid for the sins of the whole world, not just of select individuals:
John 1:
29 The next day John seeth Jesus coming unto him, and saith, Behold the Lamb of God, which taketh away the sin of
the world.
John 3:
16 For God so loved
the world, that he gave his only begotten Son, that
whosoever believeth in him should not perish, but have everlasting life.
John 6:
51 I am the living bread which came down from heaven: if
any man eat of this bread, he shall live for ever: and the bread that I will give is my flesh, which I will give for the life of
the world.
1 John 2:
2 And he is the
propitiation for our sins: and not for ours only, but also for the sins of
the whole world.
1 John 4:
14 And we have seen and do testify that the Father sent the Son to be the Saviour of
the world.
1 Timothy 2:
6 Who gave himself a ransom for
all, to be testified in due time.
1 Timothy 4:
10 For therefore we both labour and suffer reproach, because we trust in the living God, who is the Saviour of
all men, specially of those that believe.
2 Corinthians 5:
14 For the love of Christ constraineth us; because we thus judge, that if one died
for all, then were all dead:
Hebrews 2:
9 But we see Jesus, … that he by the grace of God should taste death for
every man.
2 Peter 3:
9 The Lord is not slack concerning his promise, as some men count slackness; but is longsuffering to us-ward, not willing that
any should perish, but that
all should come to repentance.
Secondly, the universality of Atonement does not translate into universality of salvation. Christ has atoned for the sins of
all men so that
all might have the opportunity to “come unto repentance” (2 Peter 3:9) and be saved. The fact that some fail to do so is their problem, not God’s doing.
Humans are either united to Adam or united to Christ. Each person is either a child of the devil or a child of God through adoption. Do you call on God as your Heavenly Father in this life?
That is a meaningless statement. All men are the children of God (Acts 17:28). Adam was the son of God (Luke 3:38). The “adoption” that Paul talks about refers to the regeneration of the sinner that takes place through repentance and faith in Jesus Christ. All men are “spiritually dead” in sin because of the Fall. The Atonement has the power to bring them spiritually back to life again trough faith, repentance, and baptism in the name of Jesus Christ. That is what is meant by being “born again”. This “new birth” or “second birth” is what the “adoption” is referring to. By this process we are born
anew into the household of Christ, and become His sons and daughters.