Look at who this passage is addressed to.
Who are the "we", the "us"?
This is not addressed to all of humanity, my friend.
Why do you insist on assigning this passage to all of mankind, when it is addressed to those who have already believed on Christ?
No my friend.
They are in Hell because they are sinners who hate God ( Romans 1:18-32 ).
Remember this?
" For the wages of sin [is] death; but the gift of God [is] eternal life through Jesus Christ our Lord." ( Romans 6:23 ).
Gifts do not need to be accepted or even known about to be received.
So now your saying that the offer of salvation is really not universal, wow you really have a warped view of theology.
Were you a sinner before you trusted in Christ Jesus? YES you were, in fact we all were.
So He died for us
Rom 5:8 But God demonstrates His own love toward us, in that
while we were yet sinners, Christ died for us.
And as we see by His death we were reconciled to God and it is by His life we are saved,
Rom 5:10 For
if while we were enemies we were reconciled to God through the death of His Son, much more, having been reconciled,
we shall be saved by His life.
But you may be asking why are we saved by His life:
Rom 5:1 Therefore,
having been justified by faith, we have peace with God through our Lord Jesus Christ,
Rom 5:2 through whom also
we have obtained our introduction by faith into this grace in which we stand; and we exult in hope of the glory of God.
Rom 10:9 that
if you confess with your mouth Jesus as Lord,
and believe in your heart that
God raised Him from the dead,
you will be saved;
Rom 10:10 for
with the heart a person believes, resulting in righteousness, and
with the mouth he confesses,
resulting in salvation.
Look at the context of the verses that I have shown you and I am sure it will clear up a number of your misunderstandings.