Mormons want to convert people so they can live in the Celestrial Kingdom or the highest kingdom. To enter into the Celestrial Kingdom you have to be baptized and be married in the temple.

Annelise, there are obviously questions that lead to more questions, and I just wanted to add a little more to the last response. We believe that there are 3 different degrees to heaven. (from lowest to highest) Telestial, Terrestrial, Celestial. (Not Celestrial. : ) ) Of course those who are good God fearing people will be able to go to heaven, but there are more requirements to be qualified to attain the Celestial Kingdom. To attain the Celestial, like was said above, you have to be baptized, and recieve certian ordinances which are given inside our Temples. One of those is \"Marriage for time and all eternity\" with your spouse. But just because you do those things doesn\'t guarantee you a one-way ticket. You still have to be faithful in keeping the commandments and keep pushing through all the way to the end. Now we don\'t know who will go to where, (Only God is the Judge of that) but we have been told what is required to attain the Celestial.

"We believe that there are 3 different degrees to heaven." 
 
Where can that be found in the Bible?

The best reference to this is found in 1st Corinthians 15:40-42. Also reference is made to it in John 14:2.