Why did seceding states believe they had to leave the union

Because the newly-elected Lincoln refused to allow the creation of any new slave-states.

The President Elected, Abraham Lincoln, was a known anti-slavery activist and he didn't allow the creation of new slave-states. As consequences, since there were more states joining the Union, the most likely scenario was a congress dominated with states that would adopt politics that could be unfavorable for the Southern States.

slavery because it wasnt a role of government

according to islamic belief there is only one god and muhammed is god´s messenger.

he was sent to introduce and instruct his people with god´s teachings : the 5 pillars of islamism. these are the five basic acts of islamic religious belief.

number one is the declaration of faith. this means there is only one god and one messenger.

number two is obligatory five prayers . number three is compulsory giving in order to achieve balance and encourage individual growth.

number five is fasting in the month of ramadan and the final number five pilgrimage to the mecca.