The Judgement of Christ is probably a misleading term for what will happen. Yes it is a time where Jesus Judges his followers but it is also a time where he rewards. The Judgement is not one of failure but degree of success. We will be rewarded on how we lived or Christian life and used the gifts we were given. This does not mean some will be treated differently because they were Christians a shorter period of time. The reward is based on how you used the time, whether 1 month or 50 years. In this way every one is judged or rewarded equally. It is not a concept that man could use as we measure years or time as needing a reward, on top of the content of that time. God sees the content first. Some one could have been a Christian for 50 years and done nothing for the first 40 whilst some one could have just been a Christian for a month and accomplished more in that month than the other did in that final year.
What we can be sure of is that Christ's judgement will be fair and just and our rewards will be appropriate for each person.