My understanding of this passage is that Gützlaff actively learned Chinese dialects, and actively chose to wear local clothes.

These were behaviours and activities under his control.

Your difficulty arises because of the passive part he has to play in becoming a member of the tribe. It is therefore more important that his passive, receiving role in becoming a member is emphasised. It is not possible for him to say: "I am one of you!" and immediately it is reality. It is the tribe that makes this decision and allows or invites him in.

So I'd suggest something like:

He let himself become admitted into the tribe.

But that seems quite inelegant, or should I say: like a germanised or quaint style? Unless a most literal translation or approximation is required, you may probably change this into the much preferred active voice variant.

He learned…, he wore… they admitted him…

Coincidentally, gTranslate agrees when translating:

He let himself become admitted into the tribe. _{into English:} Er ließ sich in den Stamm aufnehmen.

But also prefers a more modern style in the other direction:

Er ließ sich in den Stamm aufnehmen. _{into German:} He was admitted to the tribe.

But it is important to note that both variants retain his passive role in that game.

My understanding of this passage is that Gützlaff actively learned Chinese dialects, and actively chose to wear local clothes.

These were behaviours and activities under his control.

Your difficulty arises because of the passive part he has to play in becoming a member of the tribe. It is therefore more important that his passive, receiving role in becoming a member is emphasised. It is not possible for him to say: "I am one of you!" and immediately it is reality. It is the tribe that makes this decision and allows or invites him in.

So I'd suggest something like:

He let himself become admitted into the tribe.

But that seems quite inelegant, or should I say: like a germanised or quaint style? Unless a most literal translation or approximation is required, you may probably change this into the much preferred active voice variant.

He learned…, he wore… they admitted him…

Coincidentally, gTranslate agrees when translating:

He let himself become admitted into the tribe. _{into German:} Er ließ sich in den Stamm aufnehmen.

But also prefers a more modern style in the other direction:

Er ließ sich in den Stamm aufnehmen. _{into English:} He was admitted to the tribe.

But it is important to note that both variants retain his passive role in that game.

My understanding of this passage is that Gützlaff actively learned Chinese dialects, and actively chose to wear local clothes.

These were behaviours and activities under his control.

Your difficulty arises because of the passive part he has to play in becoming a member of the tribe. It is therefore more important that his passive, receiving role in becoming a member is emphasised. It is not possible for him to say: "I am one of you!" and immediately it is reality. It is the tribe that makes this decision and allows or invites him in.

So I'd suggest something like:

He let himself become admitted into the tribe.

But that seems quite inelegant, or should I say: like a germanised or quaint style? Unless a most literal translation or approximation is required, you may probably change this into the much preferred active voice variant.

He learned…, he wore… they admitted him…

My understanding of this passage is that Gützlaff actively learned Chinese dialects, and actively chose to wear local clothes.

These were behaviours and activities under his control.

Your difficulty arises because of the passive part he has to play in becoming a member of the tribe. It is therefore more important that his passive, receiving role in becoming a member is emphasised. It is not possible for him to say: "I am one of you!" and immediately it is reality. It is the tribe that makes this decision and allows or invites him in.

So I'd suggest something like:

He let himself become admitted into the tribe.

But that seems quite inelegant, or should I say: like a germanised or quaint style? Unless a most literal translation or approximation is required, you may probably change this into the much preferred active voice variant.

He learned…, he wore… they admitted him…

Coincidentally, gTranslate agrees when translating:

He let himself become admitted into the tribe. _{into English:} Er ließ sich in den Stamm aufnehmen.

But also prefers a more modern style in the other direction:

Er ließ sich in den Stamm aufnehmen. _{into German:} He was admitted to the tribe.

But it is important to note that both variants retain his passive role in that game.