John 3:36

ὁ πιστεύων εἰς τὸν υἱὸν ἔχει ζωὴν αἰώνιον· ὁ δὲ ἀπειθῶν τῷ υἱῷ οὐκ ὄψεται ζωήν, ἀλ ἡ ὀργὴ τοῦ θεοῦ μένει ἐπ' αὐτόν

The one who believes in the son has eternal life, but the one who rejects the son will not see life but the wrath of God remains on him


 * πιστεύων - a participle, present active masculine nominative sg. Note εἰς takes accusative τὸν υἱὸν.
 * ἀπειθῶν - the contrasting idea, also a participle, again present active masculine nominative sg. Note here it goes with a dative τῷ υἱῷ. A number of verbs expressing allegiance or belief go with dative.
 * ὄψεται - future middle indicative sg form of ὁράω.
 * ὀργὴ - anger, wrath
 * μένει - abides, remains, present active indicative 3P sg. form of μένω.
 * ἐπ' αὐτόν - on him. Notice how ἐπί drops the vowel as it comes before αὐτόν which starts with a vowel. ἐπί goes with genitive, dative or accusative, in this case accusative, with a typical gloss of on or at.