If you know that He is absolutely righteous, you know [for certain] that everyone who practices righteousness [doing what is right and conforming to God’s will] has been born of Him.

Beloved, we are [even here and] now children of God, and it is not yet made clear what we will be [after His coming]. We know that when He comes and is revealed, we will [as His children] be like Him, because we will see Him just as He is [in all His glory].

and not be like Cain, who was of the evil one and murdered his brother [Abel]. And why did he murder him? Because Cain’s deeds were evil, and his brother’s were righteous.