Salaam Sarder,
It is about mainly blind following what was told to them, taught to them and guidance imparted for the living and before the Day of Judgment. Verse 5:105 goes along with the previous verse, 5:104.
5:104 And when it is said to them, "Come to what Allah has revealed and to the Messenger," they say, "Sufficient for us is that upon which we found our fathers." Even though their fathers knew nothing, nor were they rightly guided.
5:105 O you who have believed, upon you is [responsibility for] yourselves/souls. Those who have gone astray will not harm you when you have been guided. To Allah is you return all together; then He will inform you of what you used to do.
This is my opinion how I have come to understand it.