ٱلَّذِينَ ءَامَنُوا وَعَمِلُوا ٱلصَّٰلِحَٰتِ طُوبَىٰ لَهُمْ وَحُسْنُ مَـَٔابٍ

The reason for the rejection of the preacher of truth is generally that the people do not find any tangible glories around this person. But this amounts to being unsuccessful at the very point where a man has to prove successful. God wants man to recognize the truth in its absolute shape and to surrender himself to that truth. Now, one who insists that he will not accept the Truth without tangible feats will be fated in this world never to find the truth according to the law of God and he will always be deprived of God’s guidance. This world is a testing ground. Here man can find God at the level of remembrance; he cannot find God at the level of ‘observation’. Those who agree with this godly plan will find God and those who do not will be unsuccessful in finding Him, just as one who insists on seeing the sun with his naked eyes will be unsuccessful in doing so. In this world only that person succeeds who accepts God’s plan and who moulds his life according to it, because it is God who is the Creator of this world and not man.

— Source: Tazkirul Quran (Maulana Wahiduddin Khan) via Quran.com (13:29)