A comment on the Roman Missal

A young woman, who has been reading the Roman Missal, that was introduced in late 2011, writes the following:

How can they expect people to listen to ramblings like this?

“For in him you have made a new covenant with your people, so that as you have redeemed man and woman by the mystery of Christ's Death and Resurrection, so in Christ you might make them partakers of divine nature and joint heirs with him of heavenly glory.”

How is anyone to understand? ”partaker of divine nature and joint heirs”