Firstly, suffering is for now . We sometimes think it's going to last forever. Thirdly, suffering comes if it is necessary. But the God of all grace , who hath called us unto His eternal glory by Christ Jesus, after that ye have suffered a while, make you perfect, stablish strengthen, settle you. Suffering is a refining process.
Character is refined.
It is interesting that Jesus used a mustard seed as His example. They wanted their faith to be bigger, Jesus talks about something smaller. A mustard seed can't be destroyed by water. Water won't turn a mustard seed sour unlike other seeds. A mustard seed will survive being soaked in water.