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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. They are an Indigenous people, in the New Guinea people cluster of the Pacific Islander Peoples 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
View on Joshua Project

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Pray for the Big Sepik of Papua New Guinea

Join others around the world in praying for the lost to be saved, the gospel to advance, the global Church to grow, and for laborers to be sent out and sustained in the harvest.

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Dig Deeper (Religion):

Primary Religion: Christianity - Roman Catholicism
Religious Affiliation: Christianity

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Dig Deeper (Language):

Primary Language: Iatmul
Language Family: Ndu

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Media Resources in Iatmul:

Films:

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Provided by the Jesus Film Project

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Bible Resources in Iatmul:

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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

Claiming to be wise, they became fools.
readRomans 1:22

Ask God to pour out His mercy and bring those who are walking in their own wisdom to faith in Jesus.

And many nations shall join themselves to the LORD in that day, and shall be my people. And I will dwell in your midst, and you shall know that the LORD of hosts has sent me to you.
readZechariah 2:11

Pray that many will take refuge in the Lord and be His people who share the good news of salvation in Jesus with others.

Blessed is the man who remains steadfast under trial, for when he has stood the test he will receive the crown of life, which God has promised to those who love him.
readJames 1:12

Pray that as people place their faith in Christ, they will be encouraged when they persevere under trial, knowing that when they have stood the test, they will receive the crown of life.

Wash me thoroughly from my iniquity, and cleanse me from my sin!
readPsalm 51:2

Pray that God will raise up believers to go and share the gospel with those in this people group who need to be washed of their iniquity and cleansed from their sins.

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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