"Jesus be with you!"
Because akua is a "common noun", it usually has a noun marker in front of it. The common way to express "God", with a capital G, in Hawaiian is with "ke Akua" (with a capital A). When referring to other akua, a lower case a is the norm. Iesū is a name, so it doesn't appear with a regular noun marker in front of it.
Pū is an interesting word. Some definitions for this usage of pū are: together, entirely, completely, also with, together with (from Pukui-Elbert Hawaiian Dictionary). It is often used as an "adverb" after "verbs" like hele, e.g. "E hele pū kākou" -> "Let's go together".
It can also be used after pronouns, for example, in the phrases "ʻO au pū" -> "Me too" and "Me ʻoe pū" -> "same to you [as in reply to a good wish]" (Pukui-Elbert Hawaiian Dictionary).
Hawaiian was an oral language. The 19th century missionaires, however, were supposed to teach their converts to read the Bible. They created a writing system with an alphabet of only twelve letters for words of indigenous Hawaiian origin.
RonRGB: "Iesū pū." was probably one of the first phrases that the missionaries would have attempted to teach the Hawaiian people as missionaries would not have had respect for the Hawaiianʻs Gods. The missionaries would have wanted the Hawaiian people to believe in Jesus (Iesū) / one God.
(Iesū used in Hawaiian) Link: http://ulukau.org/chd/baibala/baibala-conc-iesu1.htm
ʻO ke kūʻauhau na ka hanauna o Iesū Kristo, ka mamo a Dāvida, ka mamo a ʻAberahama.
A record of the genealogy of Jesus Christ the son of David, the son of Abraham:
Na Iakoba ʻo Iosepa ke kāne a Maria nāna i hānau ʻo Iesū, i kapa ʻia ʻo Kristo.
and Jacob the father of Joseph, the husband of Mary, of whom was born Jesus, who is called Christ.
Penei hoʻi ka hānau ʻana o Iesū Kristo: I hoʻopalau ʻē ʻia kona makuahine ʻo Maria na Iosepa, ʻaʻole naʻe lāua i pili, a ʻikea ʻo ia, ua hāpai na ka ʻUhane Hemolele.
This is how the birth of Jesus Christ came about: His mother Mary was pledged to be married to Joseph, but before they came together, she was found to be with child through the Holy Spirit.
A e hānau mai ʻo ia i keiki kāne, a e kapa aku ʻoe i kona inoa ʻo IESŪ; no ka mea, e hoʻōla ia i kona poʻe kānaka mai ko lākou hewa.
She will give birth to a son, and you are to give him the name Jesus, because he will save his people from their sins."
Thank you for the explanation. It is sad how native creeds were repressed. Are they still practiced in Hawai'i?
(Hawaiian Guide Link):
Over the last few centuries, people from many different countries have made Hawaii their home. With this wide range of Asian, European, and American backgrounds added to native Hawaiian heritage, a rich mix of religions gives Hawaii part of its distinctive character.
About half of Hawaii's current population practices a form of Christianity. Catholics make up the highest percentage of Christians, but Protestants aren't far behind. Almost any denomination which exists can be found (in the state of Hawaii), as well as a fair number of non-denominational churches. There's even a Mennonite church, with the state's smallest congregation with less than 100 members.
With Hawaii's large Asian population, religions from the Far East play an important role, too. Buddhism has the largest following among these religions, but Shinto, Hinduism, and other spiritual practices from the region can be found on the islands as well.
A surprisingly large number of Mormons live in Hawaii. Jehovah's Witnesses also represent a notable percentage. Several synagogues serve Hawaii's relatively small Jewish population, while one mosque serves a smaller Muslim following. A few pagan groups also exist; however, since pagans rarely build worship centers, often practice individually, tend to keep their spirituality a secret, and are lumped into "other religions" categories in census studies, estimating their numbers is almost impossible.