As far as the Baptism of Water and of Fire is concerned.
LDS believe that is is the Holy spirit that sears the sins from your spirit. Just like a fire. there have been multiple accounts of witnesses, across the globe, that saw flames encircling a person being confirmed, with the gift of the holy ghost, after baptism.
That the Baptism by immersion, in water, cleanses your body in preparation for the resurrrection.
The Baptism of Fire comes from the Holy Ghost, cleansing your spirit.
"We believe the first principals and ordinances of the Gospel are: 1st, Faith in the Lord Jesus Christ; 2nd, Repentance; 3rd, Baptism by Immersion for the remission of sins; 4th, the laying on of Hands for the Gift of the Holy Ghost."