There are two keys to determine your eternal destiny. Your belief in Jesus opens the door to eternal life with God. Your behavior after you become a Christian will determine the eternal rewards that await you in heaven.
You may ask, How can I know if the works I do for God qualify for eternal reward?
Good works must be done in love. Did you do the work because you love Jesus, because you love the people, or both? You can teach a Bible study and not love anyone in the room except for yourself. You can feed the homeless because it makes you feel good, yet show no interest and have no compassion for the people you are feeding.
Some people are angry at poverty, injustice, and various evils. We should hate poverty, injustice, and evil of every kind. But sustained anger as a primary motivation leads only to bitterness. And our anger at a situation quickly becomes anger at the people we blame for the situation. Hating people—even evil people—is against God's command to love everyone, even our enemies.
See Matthew 5:43-45:
"You have heard that it was said, 'Love your neighbor and hate your enemy.' But I tell you, love your enemies and pray for those who persecute you, that you may be children of your Father in heaven. He causes his sun to rise on the evil and the good and sends rain on the righteous and the unrighteous."
God's love flowing through us is to be the distinguishing factor that makes us different from all the other people of the earth.
When Jesus was preparing to leave the apostles, He told them:
"A new command I give you: Love one another. As I have loved you, so you must love one another. By this everyone will know that you are my disciples, if you love one another." (John 13:34-35, NIV)
One final thought: We’re pretty good at deceiving ourselves. We can have hidden motives and not even be consciously aware of them.
But the Holy Spirit will guide you as you try to complete the specific works God prepared for you to do in this life. Daily test your heart motives.