What were three reasons why the colonies had no right to rebel?

One reason it could be said the colonies had no right to rebel is that the British had every right to tax them. At the time, many political theorists argued that the people were "virtually" represented. Fewer than 10% of the people in Great Britain could vote, and more importantly, many places, especially newer cities, did not have representation in Parliament. So it was argued that the members of Parliament represented not specific areas, but...

One reason it could be said the colonies had no right to rebel is that the British had every right to tax them. At the time, many political theorists argued that the people were "virtually" represented. Fewer than 10% of the people in Great Britain could vote, and more importantly, many places, especially newer cities, did not have representation in Parliament. So it was argued that the members of Parliament represented not specific areas, but the British people as a whole. This included the colonists in North America and the West Indies. 

Another reason was that the British spent a great deal of money--indeed nearly incurred a fiscal crisis--by defending the colonies in the French and Indian War. After that war, the Crown attempted to institute policies that would help pay for these efforts. Moreover, the frontier needed British forts guarding it against Indian attacks, and this involved the expense of stationing British soldiers there. The British thought it entirely reasonable to expect that the colonial legislatures would help meet these expenses.

Finally, many of the measures that angered the colonists had in fact been around for years. The Navigation Acts, for example, placed trade restrictions on the colonies that had been long ignored in what one member of Parliament called "salutary neglect." Smugglers prospered as American merchants sought to get around these restrictions. In the 1760s, however, the Crown sought to enforce these restrictions in ways they had not done in the past, and the colonists objected. So it could be argued that the the changes in the imperial relationship did not mark the drastic departure that the colonists suggested.