What God has promised and will provide is spoken of as though it were property or wealth that one would inherit from a family member. Alternate translation: "the guarantee that we will receive what God has promised" (See: [[rc://en/ta/man/translate/figs-metaphor]])
The abstract nouns "redemption" and "possession" can be translated using the verbs "redeem" and "possess," respectively. Possible meanings of "possession" are 1) God possesses. Alternate translation: "God redeems us as his own people" Or 2) Christians possess. Alternate translation: "we take possession of our inheritance" (See: [[rc://en/ta/man/translate/figs-abstractnouns]])