Today's First Reading brings us to the end of the First Letter of John. Throughout this Letter, John was positive in exposing doctrine, and practical in exhorting his followers to counter the heretics who denied the divinity of Jesus. The word 'know' is used frequently, and three times in verses 18-20 he says 'we know'. This knowledge is the true knowledge of God - God as light, God as righteousness, and God as love - which John sets out to impart, and he does this in defiance of the heretics' claims. Knowledge to the Jews meant recognition and experience of the power and presence of God.

This experiential knowledge comes from the Spirit of God (v. 20) and is seen in the keeping of commandments, in holiness and in brotherly love, which is what "abiding in God and God in us" means. Union with the Father is through the Son of God (v.21). The divinity of Jesus is confidently and jubilantly proclaimed here, and the Letter ends with a warning against false teachings about the divinity.

With this Letter, John's main purpose is to reassure his followers that they have a share in Jesus' divine life. In getting to this point, he mentions God's willingness to answer prayers of brotherly charity. However, this power of prayer is limited to those requests which agree with His will, and is not for remission of "deadly sins". Mention of this "deadly sin" is perhaps a reference to the sin of the heretics!