Where you and I differ is that you think God's call is ineffectual and therefore the atonement is ineffectual for many.Amen. However, the cross provided the ability for the human race to be saved since by one man’s righteousness live and grace entered the world. But the work of predestination and election are also part of the means of salvation. That is why before the cross salvation happened. Justification is a result of the cross but the total salvation package requires the work of the effectual calling of God’s elect. Without the drawing of the elect to hearing the presentation of the gospel message, they could not get saved. The elect were lost until they believed.
I think the call is always effectual because the atonement is for the elect, not for those who are eternally corrupt in their sins.