Why Prophet Muhammad (SWS) Was Not Given Clear Miracles?
Miracles in true sense are events when known laws of nature are disrupted by Allah’s command. Quran points out that signs of Allah are so numerous that it is impossible to count all of them (ref: surah Kahf, last ayat). So laws of nature help human mind know that there is a Creater, who spoke to mankind and we have His last book revealed to His last prophet PBUH. Revelation i.e. Quran is itself a miracle in the sense that laws of nature can’t know the means of it’s transmission nor can explain it’s existence as something man-made.
When you read the Qur’an you find God answering their doubts with logic. Considering their premises He asks them to doubt and discard their beliefs which they adopted for no reason. If the miracle were to decide the matter there was no need to send the projects, an angel would do the thr better. God shows some miracle on His own, not at the wish of the people, for the purpose for Itmam ul hujjah before punishing them. This is the rule for God. He punishes only after Itmam ul hujjah. Miracles were prequel to punishment. A faith after watching a miracle is not as good as a faith using reasoning that what is required.