The New Testament is very clear and consistent on its main tenant of salvation. It is by grace alone that we followers of Jesus achieve atonement. There is nothing we can do, no works are required. Faith and faith alone in Jesus Christ.
However, are roles in the new heaven are different story. Contrary to popular believe when we finally arrive in our promised land, we will not be praising Jesus 24/7. Yes, He will be our light literally and we will be in constant union with Him, but we will be rewarded for what we did after we were saved by grace. A true Christian wants to share his or her good news of forgiveness, renewal, and internal life. a True Christian is selfless desiring to help others. A true Christian appreciates their gifts that God has blessed them with and wants to use them in glorifying God.
This is called bearing good fruits and while it is not required for salvation it is the best indicator that an induvial has truly been born again. Jesus tells us of a parable in Matthew 13 in which a Sower planted seeds. Some fell by the way side and were devoured by fowls. Some fell upon stoney places in shallow soil and burned up in the noon day sun. Some fell among thorns and were choked out. But, some seeds fell into good ground and brought forth fruit, and harvest of 30, 60, even 100 times the original seed.