852. 20:6 Blessed and holy is he who shares in the first resurrection. This symbolically means that through conjunction with the Lord those who enter heaven enjoy the felicity of eternal life and enlightenment.

That person is called blessed who has the felicity of eternal life (no. 639). And that person is called holy (or a saint) who has enlightenment in Divine truths through conjunction with the Lord. For the Lord alone is holy, and the Divinity emanating from Him which produces enlightenment is what is called the Holy Spirit (nos. 173, 586, 666). The first resurrection symbolizes the Lord's raising a person into heaven and thus salvation, as in no. 851 above.

It is apparent from this that "blessed and holy is he who shares in the first resurrection" symbolically means that through conjunction with the Lord, those who enter heaven enjoy the felicity of eternal life and enlightenment.