Most Revd Justin Welby is expected to say the dead are "witnesses, unwilling, unjustly, wickedly, and they are martyrs in both senses of the word".
On Thursday gunmen from Somalia's al Shabaab terrorist group stormed the country's Garissa University letting the Muslims go free and killing Christians.
Reports say the militants opened fire as unsuspecting Christians were praying with their backs turned away from the attackers.
"These martyrs too are caught up in the resurrection: their cruel deaths, the brutality of their persecution, their persecution is overcome by Christ himself at their side because they share his suffering, at their side because he rose from the dead," Archbishop Justin will say, "because of the resurrection of Jesus from the dead the cruel are overcome, evil is defeated, martyrs conquer."
The Archbishop will also recall the murder of 21Coptic Christians in Libya last month: "They are martyrs, a word that means both one that dies for their faith and one that witnesses to faith. There have been so many martyrs in the last year."
He'll add: "And all these martyrs in their testimony to the resurrection point at us and ask, "in your comfort, in your great buildings which call out soundlessly to the reality of the risen Jesus, in your well organised societies, you who have lived these many decades under governments that welcome opposition, and that are led by those who seek honourably and honestly to serve the people, are you still witnesses?
"Today are we still witnesses that say, "Jesus is alive"?"