'The first resurrection,' mentioned in Revelation 20:5, 6, does not mean a first resurrection, but the essence and primary part of resurrection, which is salvation and eternal life. There is only one resurrection to life. A second does not happen, and is not mentioned anywhere in the Bible.

(References: Apocalypse Explained 6; Apocalypse Revealed 851; Revelation 20:5-6)

8767. 'And keep My covenant' means thus leading a good life, and as a consequence being joined [to the Lord]. This is clear from the meaning of 'keeping the covenant' as leading a life in accordance with the commandments, thus a life governed by good, and so being joined to the Lord. The reason why 'keeping the covenant' means leading a life in accordance with the commandments, thus leading a good life, is that the stipulations of the covenant were all the things that had been commanded, which were called testimonies, judgements, laws, and statutes, in particular the Ten Commandments. All these were also called the covenant because it was established through them. The fact that keeping them is leading a life in accordance with them is evident from the meaning of 'keeping' in the Word. Many times it speaks of hearing the commandments and keeping them, and in those places 'hearing' means accepting them in faith, and 'keeping' accepting them in life, that is, leading a life in accordance with them. The reason why 'keeping the covenant' also means being joined [to the Lord] is that in an overall sense 'a covenant' means being joined together, 665, 666, 1023, 1038, 1864, 1996, 2003, 2021, 6804. It has this further meaning because a person who leads a life in accordance with the commandments is joined to the Lord. For the commandments teach about life and also impart life, thereby opening the way to heaven and opening one's eyes to see the Lord.