Here the 1874 RLDS edition changed the possessive pronoun mine to my, the form in modern English that we expect in attributive position. The 1908 RLDS edition restored the original mine. For further discussion of the tendency in the text to replace attributive uses of mine with my, see under Omni 1:10. For each case of the possessive pronoun, the critical text will maintain the earliest reading, thus “mine own life” here in Moroni 1:3.
Summary: Maintain in Moroni 1:3 the archaic use of mine in the phrase “mine own life”, the reading of the earliest extant text.