The central feature of this chapter is that "God is love". In result His love is toward us. We know this because He has manifested His love — "Because that God sent His only begotten Son into the world, that we might live through Him."
Obviously there is a life other than the responsible life which we all live in flesh. We do not live to God unless we do so through His Son. There is a limit to the life which we have naturally. That is a life which sin has corrupted, consequently death can and does touch it. The life which we live through the Son of God is sinless and death cannot touch that.
Would we receive this life we must know that righteousness must be satisfied. The claims of God in regard to sin must be fully met. In order to this He sent His Son to be the propitiation for our sins. Wonderful love! Not that we loved Him, but He loved us. The cross then is at once the lesson book of the love of God for thereby was the basis laid upon which His righteousness has been established.
Not only so, but that love, according to verse 17 of our chapter, has so acted as to put us even now beyond the reach of judgment. "Herein is love with us made perfect (marginal reading) that we may have boldness in the day of judgment: because as He is, so are we in this world." Then verse 18 declares, "There is no fear in love; but perfect love casteth out fear: because fear hath torment." Thank God that if there is no fear, there is blessed and present response, "We love Him, because He first loved us" (verse 19).
As we run over this instructive chapter we see that there are:
Discernment, vv. 1-3;
Truth and Error, v. 6;
Love and Life, vv. 7-10;
Salvation and Judgment, vv. 14 and 17;
Fear and Torment, v. 18;
also response to the love of God, for we are able to love one another, and to love God Who has loved us. There is also communion, for we dwell in God, verse 13; there is witness, for He dwells in us, vv. 13-16. Finally, there is likeness to the Son of God, even now, verse 17.