In the past year or so, I've re-discovered my faith. I am also a Protestant.
The first thing that everyone has to understand is that by default, everyone goes to hell because everyone is born separated from God. It wasn't always like that, but it's what we have to deal with since it affects all of us in one way or another.
People say that God is unjust for sending people to hell, but think about it like this:
God embodies and represents absolute justice. Everyone has fallen short of that standard, and as a result God has to find them guilty, or else he would be acting unjustly.
Would God be any less unjust by forgiving sinful people instead? Something like that can only be done if the punishment for everyone was inflicted on someone else instead, since justice MUST be administered before God would have any RIGHT to show mercy. Jesus took that punishment on himself so I wouldn't have to. This is what justifies me and all other Christians before God.
The world HATES hearing this (for the simple reason that this message undermines the world's authority and cuts the world's pride to the quick), but it must be said: Jesus Christ is the only way to God. The reason is simple: Jesus is the only suitable sacrifice to God because Jesus (essentially God himself, in human form) is the sacrifice that God provided so justice could be served. By acknowledging and appealing to this, you inherit God's mercy. There is no other way because God did not provide any other way. This is why trying to achieve salvation through works is futile-- what could anyone POSSIBLY do that would overshadow God's own chosen sacrifice to himself?
We are all sinners and good works mean absolutely nothing. So basically, I don't have to try and be good, as long as I admit I am a sinner, I am saved and forgiven and will go to heaven.
When you are a real Christian, you don't have to try hard to do good works-- it becomes second nature to you. This is how you can tell if someone is a real Christian. This is because you are made new and you inherit a part of God's own nature. In spirit, a Christian is a new creation. (I remember the way I was back before this happened to me; now I no longer want to do the things that I was ensnared in. I am no longer interested in doing a lot of what this site teaches since nearly all of it appeals to the way I used to be; I only stick around for the financial advice, which can be used for good and to help others. )
In this way, Christians constantly aspire to do good, but we constantly fight against our own flesh, which has not been saved yet. In this way, a Christian has to fight against sin, but it will not be counted against us because we have already been made righteous in spirit.
The difference between a Christian and a non-Christian is that we have been made alive in spirit through Christ whereas nonbelievers are still dead in their spirit and are not righteous before God.