Should a fear of going to hell should be the biggest reason for following Christianity?

The question is mute.. at least from the point of view of Christianity.

If you were the most religious Christian ever, gave everything you had to charity, strove to be as good as you could be, never swore, never gossiped, never griped, etc but didn't sincerely believe then it would all be for naught. Therefore your motive for "following" is irrelevant.

Believing is the only thing of importance... so the question might be "What motivates us to believe?"

Personally I think there are two basic answers to this ...

1) Human drivers - these would include fear, piousness, cultural pressure, etc I'm not sure these things can ultimately lead to true belief although I've no doubt they can help someone go through the motions or masquerade

2) Spiritual drivers - ask many Christians about their journey into belief and they will passionately tell you that there were a series of events and coincidences that focused their mind on belief with ever increasing focus. They eventually came to the point of believing. During the process many describe it as like being carried along. After coming to belief they see and recognise the work of the Holy Spirit that used their circumstances, experience, knowledge and personality to gradually reveal the real truth. Curiously I think you'll also find that most of these Christians had no discernible motive for coming to believe else they approached with a determination to prove it false only to find it's truth (that was me!)

"Should a fear of going to hell be the biggest reason for following Christianity ?"

No, childhood indoctrination is the biggest reason for it. If there is no childhood indoctrination, it's very likely that there is no fear of hell either. ;)

No. But, its a nice safety net.

Similarly, should the fear of starvation be the biggest reason for eating? Or should one eat for nutrition of the body.

Similarly, one should seek God because he is the fulfillment of all desires and they desire to be with him. The fact that one wastes away spiritually apart from God should not be the main reason to seek God, but at least it points us in the right direction.

almost everyone believes in god, the ones who dont believe rejected god(john 3:18-21) the reason to fear is not hell, but fear god. The bible says to fear god over 200 times, and he is the one who has power to destroy both body and soul in hell(Luke 12:4-5). God gives people up to sin and wickedness(atheists for instance, romans 1:18-32) jesus is the only way(john 14:6) and god has promised to perserve the word of god(psalm 12:7).

Actually, according to Pascal's Wager, you should follow the most petty, sadistic and dumb God of them all. This because he will care the most about lowly mortals worshiping him, torture them the worst for not doing so, but will be fooled by them just worshiping him out of fear.

So if you ever find out which of the gods is the most petty, sadistic and dumb, that's the one to worship!

Loving God and loving neighbors is the reason for being a Christian.