Add punctuation: After age 45 it becomes more serious
A: After age 45, it becomes more serious.

Add punctuation: 1820 You shall teach them the statutes and the laws and shall show them the way in which they must walk and the work that they must do
A: 18:20 You shall teach them the statutes and the laws, and shall show them the way in which they must walk, and the work that they must do.

Add punctuation: He had assumed leadership of Marts PRC after Marts death in 1895
A:
He had assumed leadership of Marti's PRC after Marti's death in 1895.