religion

We understand that the more we adhere to Islam the more it would bring us happiness in this life and the hereafter. However there is a hadith whereby Abu Saeed Al-Khudri visited the Prophet (Pbuh) when he was unwell. He put his hand on a piece of velvet cloth with which the Prophet (Pbuh) had very high temperature. Abu Saeed said: “Messenger of Allah, you have a very high fever”. He said: “We are like this: our trials are very hard and our reward is multiplied.” Abu Saeed asked: “Messenger of Allah, which people have the greatest affliction?” He replied: “The Prophets (Pbuh), and then the most pious and righteous. Any one of them may be tested with poverty until he could find nothing more than a robe to cover himself with and he would wear that. Another could be tested with fleas until they almost killed him. They were more pleased with their affliction than any of you may be pleased with gifts.” (Related by Al-Bukhari in Al-Adab Al Mufrad).
This hadith implied that the stronger we adhere to Islam, the greater would be our affliction and hardship. That would mean we would suffer more and presumably would be less happy(in this world).Does not this situation contradict the premise that Islam would bring more happiness to those who adhere to it?