you cannot be a "fundamentally good" person. it's impossible. we are all good for nothing sinners. and what can a good for nothing sinner do for an all-powerful God? nothing! he's all powerful! however, he came down and died for our sins, so that me might not perish but have eternal life. perish. die?
i think the concepts of heaven and hell are rather bound with myth and opinion. noone really knows. from memory, the bible says hell is a place of great suffering and eternal gnashing of teeth. it is a firey pit, built but God for Satan and his angels. however, they are not there, as they are yet to be thrown down yet. but i think it is just for the angels. we humans, if we are not saved meerly die. nothing mroe, nothing less. i think. although i am not bny any means sure. it mgiht also be a place when you can just see God, but can't reach him, or meerly a place without God, heaven being a place that, well, is God.
and as to how to not get there? well, as i said earlier, we cannot do anything for God. however, he said that whatever we do unto the least of man, we do unto him. he has become the poor, the homeless, the outcasts of the world. the only description of judgement day is given in matthew, "i was hungry, did you feed me? i was naked, did you clothe me?". in short, the second commandment is a nice place to go about getting into heaven, "love your neighbour". but that isn't enough! you may have helped him, but you are still a sinful person! and God cannot tolerate sin. the burden of sin must be taken from you before you can be in his presence. in the OT, it was passed onto a sacrafice, a lamb or a calf of whatever. that was you asking for forgiveness. but now, Jesus died for our sins. he was the lamb, the greatest sacrafice ever made! he is the only one worth to come before God, and yet he died so that we could! but how do we receive this Goft of Life? is he going to give it to those who hate him? who despise him? no! he is going to give it to those who love him, and to those who ask. bascially, you must come before God and ask for it. is that so hard? people argue day and night about this and that, that you can't god to heaven unless you do communion, are baptised etc, but all you really need to do are three things. love your neighbour. love God. and ask for forgiveness. isn't that beautiful? and yet so simple.