Some people in this Present era believe that If somebody visits the graves of Pious people and take them as a means to Allah or seeks blessing through their relics, then this act is either Shirk or Biddah. Some even claim that this act wasn't done by Sahaba or in past centuries. Let us now see this in light of Quran and Hadith
وَكَذَلِكَ أَعْثَرْنَا عَلَيْهِمْ لِيَعْلَمُوا أَنَّ وَعْدَ اللَّهِ حَقٌّ وَأَنَّ السَّاعَةَ لاَ رَيْبَ فِيهَا إِذْ يَتَنَازَعُونَ بَيْنَهُمْ أَمْرَهُمْ فَقَالُوا ابْنُوا عَلَيْهِم بُنْيَانًا رَّبُّهُمْ أَعْلَمُ بِهِمْ قَالَ الَّذِينَ غَلَبُوا عَلَى أَمْرِهِمْ لَنَتَّخِذَنَّ عَلَيْهِم مَّسْجِدًا
Quran states: Thus did We make their case known to the people, that they might know that the promise of Allah is true, and that there can be no doubt about the Hour of Judgment. Behold, they dispute among themselves as to their affair. (Some) said, "Construct a building over them": Their Lord knows best about them: those who prevailed over their affair said, "Let us surely build a place of worship over them." (18:21)