Paul uses personification here as he speaks of "confidence" as if it were alive. Alternate translation: "we are very confident that we will receive the things that we wait for" (See: [[rc://en/ta/man/translate/figs-personification]])
Here "hearts" represents a person's thoughts, feelings, or inner person. The phrase "the love of God has been poured into our hearts" is a metaphor for God showing love to his people. This can be stated in active form. Alternate translation: "because he has loved us greatly" or "because God has shown us how much he loves us" (See: [[rc://en/ta/man/translate/figs-metonymy]] and [[rc://en/ta/man/translate/figs-metaphor]] and [[rc://en/ta/man/translate/figs-activepassive]])