Mother Teresa did nothing but good works all her life thinking that she was earning herself a place with God in Heaven, but on her death bed she didn't even know if she was saved, matter of fact she had doubts about God. This is all over the place in the Church because too many Christians just do man made traditions and works thinking that they are earning something when all they had to do in the first place is just believe. Jesus already did the hard work at the cross. Mormons are bad with this. Some actually think that if they do enough works that they are gonna become little gods after death.
If you read the writings of Mother Teresa, it appears that she was going through a "dark night of the soul," which happens to those who get very close to go. St. John of the Cross wrote extensively about this phenomenon.
There is no "earning" of salvation, and those who think this are either A.) ignorant of proper teaching B.) misinformed by others (including pastors) or C.) prideful, thinking that they can contribute to salvation.
I would, however, be interested in your take on the following verses which indicate that at the Judgment, Christ gives eternal life to those who have done good works:
John 5: 28-29, Rev. 20: 12-13, Matthew 25: 31-46, and Romans 2: 5-10.
*It is my opinion that salvation and eternal life are not the same thing. I can tell you why from the Bible if you are interested.
As for the issue of "becoming gods," this is a very ancient Christian teaching with which you may not be familiar. I remember that when I was Protestant, I never heard such a thing. But many of the Early Fathers taught this, and it is taken from the Bible where St. Peter says:
2 Peter 1:4
Whereby are given unto us exceeding great and precious promises: that by these ye might be partakers of the
divine nature, having escaped the corruption that is in the world through lust.
This is the glorious future of those who are Christian, that we share in the divine nature and become like God (but not in any way a partaker of His essence). The Transfiguration of Jesus on Mount Tabor is a foreshadowing of this future for mankind, and it is what mankind was created for - union with God in a communion of love.