I have posted it first in the original English and then in a modern English version, so that it can be more easily understood.

Original Version:
Secondly. It is very important that we should gain all the information we can of the snares and delusions in which these heathens are held. By this means we shall be able to converse with them in an intelligible manner. To know their modes of thinking, their habits, their propensities, their antipathies, the way in which they reason about God, sin, holiness, the way of salvation, and a future state, to be aware of the bewitching nature of their idolatrous worship, feasts, songs, etc., is of the highest consequence, if we would gain their attention to our discourse, and would avoid being barbarians to them.
This knowledge may be easily obtained by conversing with sensible natives, by reading some parts of their works and by attentively observing their manners and customs.

Modern English Version:
Secondly, it’s crucial for us to gather as much information as possible about the traps and misconceptions that these people hold. This will help us communicate with them in a clear and meaningful way. Understanding their thought processes, habits, preferences, dislikes, beliefs about God, sin, holiness, salvation, and the afterlife is essential. We also need to recognize the captivating nature of their idol worship, festivals, songs, and so on.
This knowledge is vital if we want to engage them effectively and avoid appearing alien to them. We can easily acquire this understanding by talking to knowledgeable locals, reading some of their writings, and closely observing their customs and behaviours.

Have a look at: https://learn.fieldpartner.org/crossing-cultures-101-bundle
Take time to watch the “Know Yourself” teaching that expands the thinking around Article 2.