Some Christians treat Heaven like an exclusive college: we may not have to know all of the answers perfectly, but if we don't get good enough scores on our SATs, or if our GPA or class rank is too low, we won't get in. We work hard to make the cutoff, putting in extra credit work here and there in an effort to raise our scores. We evangelize, give to charity, attend church, pray, fast, and so on, and we piously say that we are storing up for ourselves treasures in Heaven, that our Reward will make all of this suffering and sacrifice worthwhile, that we are carrying our crosses and bearing our thorns for the glory of His name.
Some Christians, on the other hand, don't really spend that much time thinking about the afterlife. We know that it's there, and we are reasonably certain of our chances of getting there, but we don't worry about it beyond that. When we pray, we do so because we want to talk to God, not because we know that we are "supposed" to pray. When we do extra credit work, we do it because we care about other people and want to reach out to them in love, not because we are trying to get more points or win more souls to Christ. We just want to give of our plenty to those who are in need, whether that giving is in the form of money, time, or abilities.
When Jesus was asked to choose the greatest of the commandments, He said to love God with everything we have, and to love one another at least as well as we love ourselves. Now, He did give us lots of other instructions about how to go about loving God and people, but at bottom, everything He said comes back to those commandments. Love God, love people. We should love one another because we are all human beings, and we are all brothers and sisters in the human race. We are all made in God's image. You don't help your little sister tie her shoes because you think your mom will give you money for it (at least, most of the time you don't). You do it because she is your sister, and no matter how annoying it is to have to take care of her, and teach her how to do things, and delay your life to make sure that hers gets on track, you still love her (grudgingly, exasperatedly, deeply), because she is your sister.
(NB: Jesus did not say that we have to like everyone. Just that we have to love them. In Mere Christianity, C. S. Lewis said that the key to this passage is "loving as you love yourself". Think of the way you love yourself: you may not wake up every day thinking, "I am awesome. I wish I could spend more time with me. I am simply the coolest thing since sliced bread," but you still love yourself. You take care of yourself, not because you are awesome, but because you are you. You try to take care of your own best interests, to preserve your health and dignity, to make yourself happy and content. We should love one another in this way, even when we don't particularly want to be friends with one another.)
I don't think God worries too much about what your score is. I think He knows the difference between someone who is searching for Him and someone who is trying to find the right answer, and i think that He grades on effort, not on results. Consider 1 Samuel 16:7, where Samuel is trying to find the next King of Israel. He keeps guessing wrong, and God tells him not to fixate so much on how things look, but to pay attention to what is inside. In other words, don't tally the score, just look at the intent. Or look at Psalm 37:23-24, where the psalmist praises God's protection of His loved ones. We're going to make mistakes, but we're not going to totally implode, because God is protecting us. He knows the hearts of those who love Him.
In The Last Battle (this is a very C. S. Lewis-heavy post), Aslan has a conversation with a guy who has served Tash (a false, evil god) his whole life. Aslan reassures him of his place in Heaven, saying (this is a paraphrase): "I am so good that any good done in the world is done in my name. And Tash is so evil that any bad done in the world is done in his name. Once people start looking to do good for its own sake, they are really looking for me, and once they look to do bad for its own sake, they are really looking for Tash. You would not have looked so hard or so earnestly if it wasn't me you were looking for."
God isn't playing games. He's not going to keep you out of Heaven because you scored below a certain level, or because you didn't learn all of the required vocabulary, or because your letter of recommendation was not sufficiently impressive. He knows the hearts of those who are truly seeking Him, and He has promised that those who seek will find.