There are 2 words here which are translated in the KJV as “believe.”  The first is “pisteuo” which means to believe in and commit oneself unto; the second is “apeitho” which means to not comply with, to refuse to obey or believe.  The second carries with it the sense of obedience.  Faith and action are linked together in this verse.  If one believes in and commits oneself to Jesus, he will act accordingly; or as James says, “Faith without works is dead.” (James 2:20, 26)

James 2:20  You foolish man, do you want evidence that faith without deeds is useless?

James 2:26  As the body without the spirit is dead, so faith without deeds is dead.

“has” shows that eternal life is secured at the moment of believing upon Jesus.  Why is this important?

“the Son” is used absolutely.  We may become the children of God by believing upon the Christ and then we are God’s sons, but Jesus is still “the” Son; there is no one like Him, even in the relationship He has with the Father.

The wrath of God is a very real thing.  As Morris points out, “Unless we are saved from real peril there is no meaning in salvation.” (p. 250)  God’s wrath is a necessary result of His character.  He is holy and is ready to act against moral evil.  F.V. Filson states, “The wrath of God, the divine judgment, immediately and relentlessly rests on the unrepentant sinner who stubbornly rejects the offer of grace and life.  There is no place for neutrality.  Man was made as a moral being who can really live only by being obedient to his Father.  He must either believe, obey God, and find eternal life, or refuse and so suffer the ruin that his evil choices make inevitable.” (qt’d in Morris p. 250)

What significance does the word “remains” have for you in this sentence?