dear, it is in the human nature to like solid and tangible proofs, as curiousity and doubt are most likely to infiltrate the human soul and mind.

See for example the following verse which speaks about the father of prophets - Abraham- who, though a strong believer, asked his Lord for a tangible proof for His Abilities for his heart to be fully assured.

"And (remember) when Ibrahim (Abraham) said, "My Lord! Show me how You give life to the dead." He (Allah) said: "Do you not believe?" He [Ibrahim (Abraham)] said: "Yes (I believe), but to be stronger in Faith." He said: "Take four birds, then cause them to incline towards you (then slaughter them, cut them into pieces), and then put a portion of them on every hill, and call them, they will come to you in haste. And know that Allah is All-Mighty, All-Wise." [Quran 2:260]