Yes, I think so. I also think this is what the Bible shows us. here are a few verses:
But store up for yourselves treasures in heaven, where moth and rust do not destroy, and where thieves do not break in and steal.
Mat 5:12 Rejoice and be exceedingly glad, for great is your reward in heaven, for so they persecuted the prophets who were before you.
Luk 6:23 Rejoice in that day and leap for joy! For indeed your reward is great in heaven, For in like manner their fathers did to the prophets.
And last but not least (this is my favorite verse in the Bible...it's up there anyway)
Galatians6
Bear one another’s burdens, and so fulfill the law of Christ. 3 For if anyone thinks himself to be something, when he is nothing, he deceives himself. 4 But let each one examine his own work, and then he will have rejoicing in himself alone, and not in another. 5 For each one shall bear his own load.
Be Generous and Do Good
6 Let him who is taught the word share in all good things with him who teaches.
7 Do not be deceived, God is not mocked; for whatever a man sows, that he will also reap. 8 For he who sows to his flesh will of the flesh reap corruption, but he who sows to the Spirit will of the Spirit reap everlasting life. 9 And let us not grow weary while doing good, for in due season we shall reap if we do not lose heart. 10 Therefore, as we have opportunity, let us do good to all, especially to those who are of the household of faith.
This is why I do not see how an atheist can have the mindset that Christians are lazy or that they don't want change in our world. We are compelled, more than anyone. First, we are human just like the rest of you. We see suffering and want to prevent that if at all possible. But we also have an added incentive, because here as I have highlighted in these verses, "great is our reward in heaven" for "being generous and doing good" We do it 1. because it is needed in our world but 2. and more importantly, it is what Jesus would do.
When it says we reap what we sew, this answers your question very clearly with a resounding YES people who reap more will sew more. That is why everyday of your life is an opportunity to influence our world from a Godly perspective with meaning and Truth. Wow!
To answer your question about what those rewards are, I have to be clear that the Bible never really spells it out. We know that we cannot bring our earthly posessions into the next life. However, if absolute happiness, joy, peace, love, and God's presence is a reward to you, you will find it in the next life. Paul writes, "Yet what we suffer now is nothing compared to the glory he will reveal to us later."
It is something to look forward to. Think about living in a world with no suffering, everyone is perfect in Jesus, and we live forever. That is just part of heaven. It's pretty indescribable when you realize that it's out of this world- literally.