The Bible says that when Jesus comes to the earth the second time, he would judge everyone based on their deeds whether good or bad. The judgment is compared to sheep being separated from the goats. The sheep are those who did good things while the goats cared less to do any good thing. Jesus emphasized that when we do good to people, we do it unto God. Similarly, when we neglect to do good to people, we neglect it unto God.
As God has given us grace until Jesus returns, God does not punish those who believe in Jesus. That does not mean that God is oblivious to sin. It only means that mankind has been given a chance to repent and get right with him while time permits. But on the day of judgment, there shall no mercy be shown towards anyone whether they be Christians or the heathen.
Jesus is going to judge two kinds of people. Those who do not know God and those who did not obey the gospel. As Jesus is a fair judge, he would judge the unbelievers based on their conscience, the Jews based on the law, and the Christians based on their fruits.