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PEOPLE GROUP PROFILE

The Big Sepik of Papua New Guinea

The Big Sepik of Papua New Guinea, numbering approximately 18,500 people, are No Longer Unreached. They are an indigenous ethnic group of Papua New Guinea and can also be known as Latmul, Nyaura. They are an Indigenous people, in the New Guinea people cluster of the Pacific Islanders affinity bloc. Their primary religion is Christianity - Roman Catholicism. They primarily speak Iatmul.

Photo by Google. (2025). Image generated by Gemini 2.5 Flash: Big Sepik

Fast Facts:

Affinity Group: Asian Pacific Rim Peoples
Country: Papua New Guinea
People Cluster: New Guinea
Primary Language(s): Iatmul (ian)
Primary Religion(s): Christianity - Roman Catholicism
Population: 18,500
Strategic Progress Index (SPI): No Longer Unreached
Global Status of Evangelical Christianity (GSEC): 5% or Greater but Less than 10% Evangelical
People Group ID: PG009782

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Pray for the Big Sepik of Papua New Guinea

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Dig Deeper (Religion):

Primary Religion: Christianity - Roman Catholicism
Religious Affiliation: Christianity

%
Christianity - Roman Cath… Adherents

Dig Deeper (Language):

Primary Language: Iatmul
Language Family: Ndu

%
Iatmul Speakers

Media Resources in Iatmul:

Films:

No entries found for: Iatmul(ian). Help build some!

Provided by the Jesus Film Project

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Bible Resources in Iatmul:

Provided by Faith Comes by Hearing

Or check out the Iatmul bible resources at Bible.com

Linked from YouVersion

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Next steps for the Big Sepik

The Big Sepik are Unengaged and Unreached, which means there are less than 2% evangelical Christian populations among which there are no known efforts focused on establishing self-sustaining churches consistent with evangelical faith and practice.

Begin signifcant prayer and fasting for this group
Send cross-cultural teams to discover and research this people group
Begin gospel seed sowing and church planting among this group

Next steps for the Big Sepik

The Big Sepik are Engaged yet Unreached, which means there are less than 2% evangelical Christian populations but there are sustained efforts at establishing self-sustaining churches consistent with evangelical faith and practice.

Continue prayer and fasting for this group
Continue gospel seed sowing and church planting among this group
Begin training up local leaders to lead and develop strategies to reach their own people

Next steps for the Big Sepik

The Big Sepik are No Longer Unreached, which means there are more than 2% evangelical Christian populations and there are churches consistent with evangelical faith and practice. There is still more to be done among them.

Empower local believers to begin praying for their own people
Continue gospel seed sowing and church planting among this group
Encourage local leaders to being leading church planting strategy and looking for Unreached and Unengaged groups nearby

Pray specifically for the Big Sepik of Papua New Guinea

I am the LORD, and there is no other, besides me there is no God; I equip you, though you do not know me, that people may know, from the rising of the sun and from the west, that there is none besides me; I am the LORD, and there is no other.
readIsaiah 45:5-6

Pray that the lost among them will be delivered from the confusion of false beliefs and come to know the one true God who alone brings light and purpose to their lives.

For my eyes have seen your salvation that you have prepared in the presence of all peoples.
readLuke 2:30

Pray that the lost will see the salvation of God, and that they will trust in Jesus Christ as their Savior and Lord.

But God, being rich in mercy, because of the great love with which he loved us, even when we were dead in our trespasses, made us alive together with Christ—by grace you have been saved.
readEphesians 2:4-5

Pray that as people place their faith in Christ, they will remember God's mercy and grace and experience joy as they walk in new life with Christ.

The steps of a man are established by the LORD, when he delights in his way.
readPsalm 37:23

Pray that believers from near and far will serve here and trust in the Lord's timing as He establishes their steps.

Big Sepik (ROP3 - 101423) reported in the following countries:

To download a comprehensive people group list in spreadsheet form, visit our Research Data page.

Peoplegroups.org relies on updates from the field and other organizations for much of our data, so if you have any updates, please contact us. We use various international naming standards. For a list of these standards and fields, visit our Definitions page.

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