The Bible was written in Hebrew, Aramaic and Greek. These languages have a singular form of “you” for when the word “you” refers to just one person, and a plural form for when the word “you” refers to more than one person. However, sometimes speakers in the Bible used the singular form of “you” even though they were speaking to a group of people. This is not obvious when you read the Bible in English because English does not have different forms that indicate where “you” is singular and where “you” is plural. But you may see this if you read a Bible in a language that does have distinct forms.
Also, speakers and writers of the Old Testament often referred to groups of people with the singular pronoun “he,” rather than with the plural pronoun “they.”
Finally, Old Testament speakers and writers sometimes referred to actions that they performed as part of a group by saying ‘I’ did it when, really, the whole group was involved.
1 Now take heed that you do not do your acts of righteousness before people to be seen by them, otherwise you will not have a reward with your Father who is in heaven. 2 So when you give alms, do not sound a trumpet before yourself as the hypocrites do in the synagogues and in the streets, so that they may have the praise of people. Truly I say to you, they have received their reward. (Matthew 6:1-2 ULT)
Jesus said this to a crowd. He used “you” plural in verse 1, and “you” singular in the first sentence of verse 2. Then, in the last sentence, he used the plural again.
God spoke all these words: “I am Yahweh, your God, who brought you out of the land of Egypt, out of the house of slavery. You must have no other gods before me.” (Exodus 20:1-3 ULT)
God said this to all the people of Israel. He had taken them all out of Egypt and he wanted them all to obey him, but he used the singular form of you here when speaking to them.
This is what Yahweh says,\n“For three sins of Edom,\neven for four,\nI will not turn away punishment,\nbecause he pursued his brother with the sword\nand cast off all pity.\nHis anger raged continually,\nand his wrath lasted forever.” (Amos 1:11 ULT)
Yahweh said these things about the nation of Edom, not about only one person.
And I arose in the night, myself and a few men with me. And I was going up by the wadi at night, and I was looking intently at the wall. And I turned back, and I entered by the gate of the valley, and I returned. (Nehemiah 2:12a,15 ULT)
Nehemiah makes clear that he brought other people with him on his inspection tour of the wall of Jerusalem. But as he describes the tour, he just says “I” did this and that.
If the singular form of the pronoun would be natural when referring to a group of people, consider using it.