Here "word" stands for a message. Alternate translation: "I ask God to take care of you and to help you to keep believing the message I spoke to you about his grace" (See: [[rc://en/ta/man/translate/figs-metonymy]])
A person's faith becoming stronger is spoken of as if the person were a wall and someone were building him higher and stronger. Alternate translation: "which is able to make become stronger and stronger in your faith" (See: [[rc://en/ta/man/translate/figs-metaphor]])
This speaks about the "word of his grace" as if the word itself would give the inheritance to believers. Alternate translation: "God will give you the inheritance" (See: [[rc://en/ta/man/translate/figs-personification]])
The blessings that God gives believers are spoken of as if they were money or property that a child inherits from his father. (See: [[rc://en/ta/man/translate/figs-metaphor]])