If God is perfect, then He could not allow anyone in heaven who "sins". Who can be good all the time? Answer, nobody. What then, are we all doomed?
No. You probably know the story of Jesus since you went to Catholic school, right?

As Paul said, you either live under Law, or under Grace. All religions in the world except Christianity teach Law in some some sort or fashion. Law is being perfect in hopes of getting to heaven. How good of a chance does that give anybody? Really?

I won't spend much more room here except to tell you that living under Grace is the only way to get to heaven. Being under Grace is the sacrifice that Jesus made of his own life for us, so that we could appear perfect before God. It is free for anyone who asks for it, and it unloads the load of guilt that we carry.

Feel free to e-mail me if you want to discuss this.