This means Christ caused a better covenant between God and humans to exist.
# covenant, which is based on better promises
This can be stated in active form. AT: "covenant. It was this covenant that God made based on better promises" or "covenant. God promised better things when he made this covenant" (See: [[rc://en/ta/man/translate/figs-activepassive]])
# first covenant ... second covenant
The words "first" and "second" are ordinal numbers. AT: "old covenant ... new covenant" (See: [[rc://en/ta/man/translate/translate-ordinal]])