The Quran

قُل يا أَهلَ الكِتابِ لا تَغلوا في دينِكُم غَيرَ الحَقِّ وَلا تَتَّبِعوا أَهواءَ قَومٍ قَد ضَلّوا مِن قَبلُ وَأَضَلّوا كَثيرًا وَضَلّوا عَن سَواءِ السَّبيلِ

Muhammad Asad

Say: "O followers of the Gospel! Do not overstep the bounds [of truth] in your religious beliefs;¹ and do not follow the errant views of people who have gone astray aforetime, and have led many [others] astray, and are still straying from the right path."²

Cf.4:171. This passage, like the preceding ones, is obviously addressed to the Christians, whose love for Jesus has caused them to "overstep the bounds of truth" by elevating him to the rank of divinity; therefore my rendering, in this context, of ahl al-kitab as "followers of the Gospel".
Lit., "have gone astray from the right path": i.e., are persisting in this condition until now (Razi): an allusion to the many communities who, in the course of time, have come to attribute divinity to their spiritual leaders - a phenomenon frequently encountered in the history of religions.