For those who have never been forgiven by Jesus of their sin because they never submitted themselves to Him, their doom is sure. But, the extent of their punishment will be determined by what they did while living here on planet earth. (Revelation 20:11-15; esp. 12-13)
For those who have trusted in Jesus to forgive them and make them right before God, they will most certainly enjoy the new earth and the new heavens forever (Revelation 21:1-2ff). But, they too will be judged according to what they did (Revelation 22:12; Matthew 6:1-24 [the promise of rewards]; etc.)
How are we to respond to this truth?
We must realize that there is no way that we can earn or deserve God’s favor on our own (Ephesians 2:8-9). We are seen by Heaven’s throne as lawbreakers (Romans 3:23). We must realize that the only hope we have of being forgiven and declared righteous is by turning our back on sin and self and trusting in Jesus to forgive and save us (John 3:16; Acts 20:21). At that moment of salvation, we recognize that we no longer belong to ourselves so we spend the rest of our lives joyfully serving Jesus and showing others by our words and actions how good our God is (1 Corinthians 6:19-20).
It is in living out our faith daily that we accumulate heavenly rewards (Matthew 6:19-20). Those who are saved will stand before Jesus one day and our life will be reviewed. It is at that judgment seat that we will either receive or fail to receive rewards for what we did and why we did it (2 Corinthians 5:10). In fact, reading through Matthew 6:1-24 makes it clear that it’s not just what we do but why we do it that determines whether or not God will reward us for those actions.
So, make sure you are saved. Then live each moment to gain Heaven’s approval. Maybe no one else will see you today. (We certainly shouldn’t do our ‘good works’ so that others will see and applaud us.) But, realize that God is watching and one day, you’ll get your reward(s).