At some point in his life, Ibrahim (AS) became curious about resurrection. He knew that Allah would cause everyone to rise again after their death on the Day of Judgement, but he did not know how Allah caused something that was dead to come back to life. Ibrahim (AS) was very close to his Lord, and so one day he asked Allah to show him how it was done.
Allah responded, ‘Do you not believe?’
Of course Ibrahim (AS) did believe. He was totally submitted to Allah at all times, but he was just curious. So he said, ‘Yes I believe. But I just want to settle my heart.’
So Allah told him, ‘Take four birds and slaughter them. Cut them into pieces and put those pieces on the tops of different hills. Then call them to you and they will come to you.’
Ibrahim (AS) did exactly that. He then watched in amazement as these birds, which had just been cut up, came flying over the hills back to him. His heart was then settled.
It is not a bad thing to be curious. Ibrahim (AS) entirely believed in Allah and submitted to him, but he still had questions and Allah allowed him to ask them.