First let's deal with the word hell; where else did Jesus use this word, and when are the wicked tossed there?
This isn't the same word as hades/shoel/grave/pit, it's a proper noun, it' s place.
Mat 10:28 AndG2532 fearG5399 notG3361 (G575) them which killG615 theG3588 body,G4983 butG1161 are notG3361 ableG1410 to killG615 theG3588 soul:G5590 butG1161 ratherG3123 fearG5399 him which is ableG1410 to destroyG622 bothG2532 soulG5590 andG2532 bodyG4983 inG1722
hell.G1067
G1067, Gehenna -> Valley of Hinnom, Tophet, Valley of Slaughter: Jer 7:31-34, 19:1-12
Location: Just south of Jerusalem
https://www.blueletterbible.org/lexicon/g1067/kjv/tr/0-1/
Mark 9:43-44
43 If your hand causes you to sin, cut it off. It is better for you to enter into life [a]maimed, rather than having two hands, to go to
hell (G1067), into the fire that shall never be quenched— 44 [c]where
‘Their worm does not die
And the fire is not quenched.’
Isaiah 66:22-24
22 “
For as the new heavens and the new earth
Which I will make shall remain before Me,” says the Lord,
“So shall your descendants and your name remain.
23 And it shall come to pass
That from one New Moon to another,
And from one Sabbath to another,
All flesh shall come to worship before Me,” says the Lord.
24 “And they shall go forth and look
Upon the corpses of the men
Who have transgressed against Me.
For their worm does not die,
And their fire is not quenched.
They shall be an abhorrence to all flesh.”
Now that we see it's during the "new heavens and new earth" that the wicked will be thrown into Gehenna and all flesh will look upon the corpses year after year when they go up to Jerusalem to keep the Feasts and Sabbath. Meaning, "hell" isn't some mystical unknown place in another realm, it's literally south of where the Kingdom will be.
Verse in question:
Matthew 10:28
28 And do not fear those who
kill the body but cannot kill the soul life. But rather fear
Him who is able to destroy both soul life and body in [a]hell.
Who has the power over life, God. Don't fear those you can kill you now. Fear the one who can kill you now and take away your life of the future (after life).
Contrasting
body=present state versus life=eternal life.
Compare the two verses, soul can be defined as life.
Mat 10:28 AndG2532 fearG5399 notG3361 (G575) them which killG615 theG3588 body,G4983 butG1161 are notG3361 ableG1410 to killG615 theG3588
soul:G5590 butG1161 ratherG3123 fearG5399 him which is ableG1410 to destroyG622 bothG2532
soulG5590 andG2532 bodyG4983 inG1722
hell.G1067
Mat 6:25 ThereforeG1223 G5124 I sayG3004 unto you,G5213 Take no thoughtG3309 G3361 for yourG5216 life,G5590 whatG5101 ye shall eat,G5315 orG2532 whatG5101 ye shall drink;G4095 nor yetG3366 for yourG5216 body,G4983 whatG5101 ye shall put on.G1746 IsG2076 notG3780 theG3588 lifeG5590 moreG4119 than meat,G5160 andG2532 theG3588 bodyG4983 than raiment?G1742