The Pagan Holy Trinity
When Christians think of the Holy Trinity, the idea of the Father, Son and Holy Spirit is evoked, but the idea of a Holy Three isn't just a Christian ideal. In fact, the trinity arises long before Christianity. One example is from ancient Egypt. The legend of Osiris and his sister-wife, Isis, has the same basic structure as the Christian version, except that this story is far older.
Osiris and Isis governed the lands together with firm, but loving hands. Osiris was very knowledgeable and wanted to help his people as much as he could, so he would venture away from his home to the outer lands where he would teach the people better farming techniques and instill other knowledge to them to help them prosper.
While he was away on one of his trips, his brother, Set, a man driven by hatred and jealousy of his brother, plotted with a group of conspirators, to get rid of Osiris so he could rule the land. Being brothers, Set knew Osiris' exact measurements and cleverly designed a fabulous box built to those measurements. Upon his brother's return, Set threw an elaborate banquet in his honor, giving as a prize, the box, but only to the man who could fit it perfectly.
Being pure of heart and mind, Osiris couldn't see any harm and climbed into the box to see if he would fit. He did, but before he could get out, Set and his conspirators closed the lid and sealed it with molten lead. They carried it to the Nile and threw it in.
Later, Isis came looking for her husband and was told what Set had done. Distraught, she went in search of the sarcophagus and spent many days looking. Finally, she was told that the box had washed up on the shore in Phoenicia at the base of a Tamarisk tree. This tree grew up around the box and encased it within its trunk.
The Phoenician king liked the huge tree so much that he had it cut down and made into a pillar in his palace. Hearing of this, Isis met with the queen and told her of Set's trickery. Moved by Isis' plight, the queen returned the box containing Osiris.
Isis took it back to Egypt and brought out her husband's body. She then changed herself into a bird, cast a spell and became pregnant with a son, Horus. She next went to Thoth, the scribe god, and asked to have Osiris brought back to life, but before he could complete the ritual, Set found the body and dismembered it into 14 pieces, scattering them throughout the land. Isis refused to allow Osiris to be lost and set about to locate all of the pieces. She found all but one, the phallus, and brought them back to Thoth, who, with help from Anubis, Lord of the Dead, carefully sewed the body back together and wrapped it in linen. He then performed the Opening of the Mouth ritual, which allowed Osiris' spirit to re-enter his body and bring him back to life. Unfortunately, since the dead are forbidden to remain among the living, Osiris became the ruler of the Underworld.
With Osiris safely in the Underworld, Set challenged Horus' claim to the throne and they fought. Horus ended up victorious and Set was condemned to the darkness. Osiris watches over the dead and Horus watches over us in life.
This legend gives us Osiris in his mummified form representing the Tree of Life, the Axis Munde or the World Pillar. This story is also the origin of the Trinity and Resurrection in Christianity. The Trinity aspect is formed by Osiris, Isis, the Holy Mother, and Horus, who was born of the spirit of Osiris. It's not much of a leap to see how this ties into Christianity, or any of the other religions for that matter. The assimilation of ideas from various cultures enriches and familiarizes a religion, making it more acceptable to those around. In this way, a new religion or belief system can be introduced and accepted much easier by the people.