"He sure doesn't use fear"?
What Bible are you reading?
Just off the top of my head, I can think of MULTIPLE INSTANCES where Jesus, the apostles, or the prophets used fear as a motivator while warning their hearers about hell-fire and damnation.
For example, Jesus certainly had high praises for his forerunner, John the Baptist, and John preached the following:
Matthew chapter 3
[1] In those days came John the Baptist, preaching in the wilderness of Judaea,
[2] And saying, Repent ye: for the kingdom of heaven is at hand.
[3] For this is he that was spoken of by the prophet Esaias, saying, The voice of one crying in the wilderness, Prepare ye the way of the Lord, make his paths straight.
[4] And the same John had his raiment of camel's hair, and a leathern girdle about his loins; and his meat was locusts and wild honey.
[5] Then went out to him Jerusalem, and all Judaea, and all the region round about Jordan,
[6] And were baptized of him in Jordan, confessing their sins.
[7] But when he saw many of the Pharisees and Sadducees come to his baptism, he said unto them, O generation of vipers, who hath warned you to flee from the wrath to come?
[8] Bring forth therefore fruits meet for repentance:
[9] And think not to say within yourselves, We have Abraham to our father: for I say unto you, that God is able of these stones to raise up children unto Abraham.
[10] And now also the axe is laid unto the root of the trees: therefore every tree which bringeth not forth good fruit is hewn down, and cast into the fire.
[11] I indeed baptize you with water unto repentance: but he that cometh after me is mightier than I, whose shoes I am not worthy to bear: he shall baptize you with the Holy Ghost, and with fire:
[12] Whose fan is in his hand, and he will throughly purge his floor, and gather his wheat into the garner; but he will burn up the chaff with unquenchable fire.
John the Baptist, as he was "preparing the way of the Lord" (vs. 3), told people to "repent" (vs. 2), and to "bring forth fruits worthy of repentance" (vs. 8). He also told them that Jesus would "hew down every tree which wasn't bringing forth good fruit, and cast it into the fire" (vs. 10) or "burn up the chaff with unquenchable fire" (vs. 12) while "warning the people to flee from the wrath to come" (vs. 7).
Perhaps your Bible says that John told these people "God loves you and has a wonderful plan for your life" or "Smile, Jesus loves you"?
Jesus preached the same thing that John preached;
Matthew chapter 7
[17] Even so every good tree bringeth forth good fruit; but a corrupt tree bringeth forth evil fruit.
[18] A good tree cannot bring forth evil fruit, neither can a corrupt tree bring forth good fruit.
[19] Every tree that bringeth not forth good fruit is hewn down, and cast into the fire.
And what about Jesus' parables?
From the parable of the wheat and the tares:
Matthew 13;30
[30] Let both grow together until the harvest: and in the time of harvest I will say to the reapers, Gather ye together first the tares, and bind them in bundles to burn them: but gather the wheat into my barn.
Here's his own interpretation of the same:
[40] As therefore the tares are gathered and burned in the fire; so shall it be in the end of this world.
[41] The Son of man shall send forth his angels, and they shall gather out of his kingdom all things that offend, and them which do iniquity;
[42] And shall cast them into a furnace of fire: there shall be wailing and gnashing of teeth.
That certainly sounds like hell-fire preaching to me, and I could easily cite many more examples from Jesus' own lips.
You don't think that Jesus used fear as a motivator?
What about this?
Luke chapter 12
[1] In the mean time, when there were gathered together an innumerable multitude of people, insomuch that they trode one upon another, he began to say unto his disciples first of all, Beware ye of the leaven of the Pharisees, which is hypocrisy.
[2] For there is nothing covered, that shall not be revealed; neither hid, that shall not be known.
[3] Therefore whatsoever ye have spoken in darkness shall be heard in the light; and that which ye have spoken in the ear in closets shall be proclaimed upon the housetops.
[4] And I say unto you my friends, Be not afraid of them that kill the body, and after that have no more that they can do.
[5] But I will forewarn you whom ye shall fear: Fear him, which after he hath killed hath power to cast into hell; yea, I say unto you, Fear him.
Do you fear the one who has power to cast into hell?
I do.
As I've said here (and elsewhere) many times in the past, the number one problem in BOTH the world AND the church (you can hardly distinguish between the two in many/most cases) is the lack of the fear of God.
And what about Jesus' commission to his apostles?
Have you never read the following?
Mark chapter 6
[7] And he called unto him the twelve, and began to send them forth by two and two; and gave them power over unclean spirits;
[8] And commanded them that they should take nothing for their journey, save a staff only; no scrip, no bread, no money in their purse:
[9] But be shod with sandals; and not put on two coats.
[10] And he said unto them, In what place soever ye enter into an house, there abide till ye depart from that place.
[11] And whosoever shall not receive you, nor hear you, when ye depart thence, shake off the dust under your feet for a testimony against them. Verily I say unto you, It shall be more tolerable for Sodom and Gomorrha in the day of judgment, than for that city.
[12] And they went out, and preached that men should repent.
The apostle preached REPENTANCE, and they shook the dust off their feet as a testimony against those who refused the same while understanding that it would be more tolerable for Sodom and Gomorrha on the day of judgment than for those who refused the gospel. In case you haven't heard, Sodom and Gomorrha were wiped out by FIRE AND BRIMSTONE.
How about Paul?
What was his motivator?
II Corinthians chapter 5
[10] For we must all appear before the judgment seat of Christ; that every one may receive the things done in his body, according to that he hath done, whether it be good or bad.
[11] Knowing therefore the terror of the Lord, we persuade men; but we are made manifest unto God; and I trust also are made manifest in your consciences.
How about you?
Do you know THE TERROR OF THE LORD?
If you're like most professing "Christians", including quite a number of those on this website, then you most certainly don't.
Anyhow, to the OP's question, the apostles preached exactly what Jesus told them to preach:
Luke chapter 24
[46] And said unto them, Thus it is written, and thus it behoved Christ to suffer, and to rise from the dead the third day:
[47] And that repentance and remission of sins should be preached in his name among all nations, beginning at Jerusalem.
[48] And ye are witnesses of these things.
Of course, Paul preached the same thing:
Acts chapter 26
[12] Whereupon as I went to Damascus with authority and commission from the chief priests,
[13] At midday, O king, I saw in the way a light from heaven, above the brightness of the sun, shining round about me and them which journeyed with me.
[14] And when we were all fallen to the earth, I heard a voice speaking unto me, and saying in the Hebrew tongue, Saul, Saul, why persecutest thou me? it is hard for thee to kick against the pricks.
[15] And I said, Who art thou, Lord? And he said, I am Jesus whom thou persecutest.
[16] But rise, and stand upon thy feet: for I have appeared unto thee for this purpose, to make thee a minister and a witness both of these things which thou hast seen, and of those things in the which I will appear unto thee;
[17] Delivering thee from the people, and from the Gentiles, unto whom now I send thee,
[18] To open their eyes, and to turn them from darkness to light, and from the power of Satan unto God, that they may receive forgiveness of sins, and inheritance among them which are sanctified by faith that is in me.
[19] Whereupon, O king Agrippa, I was not disobedient unto the heavenly vision:
[20] But shewed first unto them of Damascus, and at Jerusalem, and throughout all the coasts of Judaea, and then to the Gentiles, that they should repent and turn to God, and do works meet for repentance.
I'll stick with the likes of John the Baptist, Jesus, and the apostles.