The whole problem with this thread is that everyone has it upside down and inside out. It isn't that atheists might be getting a judgement that we, in our own human estimations, think is unwarranted. Its that a select few are escaping a righteous judgement, that they, in God's estimation, truly do deserve. Any
real believer I've ever met or even read about has obeyed God's commands not from a desire to obtain God's favor, but out of a sense of gratitude for the salvation that has already been granted. This deals with the notion that scripture somehow contradicts itself. Both are true. Salvation is of grace--you can't earn it (this is the doctrine of Divine Election, Belgic Confession of Faith - article 16). Believers work out their salvation--your status as "saved" will be evidenced through your actions (this is the doctrine of Sanctification of Sinners, Belgic Confession of Faith - article 24).
Historic Church Documents at Reformed.org