As I read this article (which Jason referenced yesterday), I found that there was one excellent point the author made- even if he drew some very bad conclusions from it:
"Both Peter and Judas committed the same sin. They both denied Jesus."
Take away everything you know about the two men; in fact, take away the results of the two sins. We can certainly say that these two sins were extremely similar. In fact, we might tilt the scale the other way by saying that Peter's sin (Mark 14:66-72) was one of actual denial, but Judas' sin (Mark 14:43-45) was actually affirming his relationship with Jesus. So these two men definitely sinned in similar ways.
The differences are not mainly in the events themselves, that is, the actual sins. Furthermore, what separated Peter and Judas wasn't in the amount of time they spent with Jesus, the number of things they did for Jesus, not even their response to their own betrayal of Jesus. Yes, it's true that we can look at Judas' life and see that he is portrayed as different (in a bad way) from the rest of the twelve, and we can see that Peter was within Jesus' inner-circle, and even said a wonderful truth or two. But what separated them (and what still separates them) can't be found merely within them, it's within Jesus.
Let's narrow it to three scenes...
Before the Cross
Jesus foretold of Peter's denial. He tells him, "Simon, Simon, behold, Satan demanded to have you, that he might sift you like wheat, but I have prayed for you that your faith may not fail. And when you have turned again, strengthen your brothers." (Luke 22:31-32) Here we see Jesus praying for Peter, interceding on his behalf.
Jesus also foretold of Judas' betrayal. However, in Judas' case Jesus turns to him and says, ""What you are going to do, do quickly." Jesus doesn't acknowledge that it's going to happen but that he is interceding for him, he allows the sifting to begin.
After the Cross
Let's move past Christ being put to death, past him being laid in the tomb, and past the tomb being found empty. You are probably familiar with Peter deciding to go fishing, having no luck, and Jesus calling out to him, telling him to cast his net on the other side of the boat. Peter's catch was so big it reminded me of Finding Nemo ("just keep swimming"), but Peter didn't care about the catch, he cared about the one standing on the bank. He threw himself into the water and swam to Jesus and, after breakfast, he and Jesus had a heart-to-heart that revealed a little about Peter and a lot about Jesus.
Jesus asked Peter, "do you love me?" "of course" Peter replied. So Jesus told him to feed his lambs. Maybe the issue was settled, but not for Jesus, he asked Peter the same question again and received the same reply and Jesus told him to tend his sheep. Finally, a third time Jesus asked Peter, "do you love me?" Peter tearfully affirmed his love for Jesus one last time. Jesus told him to feed his sheep. This beautiful picture of restoration goes beyond a discussion of the number three or Greek words for love. In the end, this tells us something about the cross, namely, that Peter's denial of Jesus drove the nails through Christ's wrists in order that he may be forgiven and restored.
As for Judas, it may seem that little could be said about him after the cross, he was dead. Was his suicide driven by repentance or self-pity? I could guess but I'm not sure that would be the best way to know about his fate. Instead, consider instead that the entire record of Judas' life, betrayal, and death were written after the cross. In other words, just as Peter's story was recorded through the lens of Holy Spirit inspired writers, through the lens of his restoration, the story of Judas was also portrayed in a certain light (or lack thereof).
It's probably best not to interpret the account of Judas' suicide by what wasn't said, namely, that he repented. But consider what was recorded after the cross about Judas' betrayal:
"So, after receiving the morsel of bread [which indicated that he was to betray Jesus], he [Judas] immediately went out [to betray Jesus]. And it was night." (John 13:30)
Now we're talking about something that was said, but why was it said? The word "night" is used 6 times in John's gospel, and in only one of those instances is it obviously indicated that all John means by using the word is to give us an idea of what time it was (a passing reference in 21:3). Usually, it is meant to indicate sinfulness, darkness of the heart, one who does not (or does not yet) believe in Jesus.
Consider Nicodemus, who came to Jesus "by night" in John 3:2 and Jesus told him he "must be born again" (3:7). Then, after Nicodemus' conversion, he shows up as a follower of Jesus and John remarks, "Nicodemus also, who earlier had come to Jesus by night, came bringing a mixture of myrrh and aloes, about seventy-five pounds in weight." In other words, the first time he came to Jesus he was in darkness but not anymore!
In my opinion, this helps us indicate that John, under the inspiration of the Holy Spirit, was telling us that Judas was not equal to a true disciple of Jesus at his betrayal and almost certainly never became one after his betrayal.
At the Cross
What is more important than any event we look at is the cross, in which both Peter and Judas participated in putting Jesus to death.
Peter had previously tried to protect Jesus (Matt. 26:51) and it is doubtful that he could have helped Jesus even if he weren't busy denying him. However, he was very much there. He was there in a very real way, a very horrifying way, and a very glorious way. I know this because the forgiveness and restoration that we saw in the last section wasn't free; it had to be paid for. Christ took on the entirety of God's wrath toward Peter's sin (Col. 2:13-14, Rom. 3:25-26) in order that the Father could justly declare Peter to be righteous in Christ. We know that Peter is in the presence of the Father because he was at the cross.
As for Judas, he was not at the cross. Unless something happened that the authors of Scripture didn't indicate: Christ was not his mediator, he was not his Lord, and he was not his savior. Had Judas turned to Christ for forgiveness, even after his betrayal, he would have been forgiven. But Judas chose darkness and will forever be in darkness.
The thing to remember is that it was not because Judas' sin was worse than Peter's sin. If not for grace, I would have been the one betraying Christ with a kiss. If not for grace, you would have literally drove the nails through his wrists. However, my hope is that you were there as I was and as Peter was. I hope that the record of debt that stands to condemn you was put away at that cross and that you are now declared righteous in the sight of the Father. Maybe you are coming to Jesus by night right now, but if you would only put your trust in him for salvation you can walk in his glorious light.
Grace and Peace,