Dear Omar:

Your friend in correct that there are similarities with many pre-Christian mythologies. The ideas of a virgin birth, sacrifice, death on the Cross, resurrection can be found in several pagan mythologies. This fact, however, does not invalidate, threaten, or change the significance of these things in Christianity.

There is only One God, who create the universe. In His creation of man He instilled within him the knowledge of Himself as God. All people have this basic knowledge. As such, when man tries to understand God he tries as best he can according to the knowledge that he has.

Before God revealed Himself to man through Israel and more fully in His Son, Jesus Christ, people had an understanding of God only from natural law and the inherent knowledge instilled within him. Without more explicit guidance from the Revelation of God,  man developed many rituals and practices in an attempt to seek and reach God. These rituals and practices were very imperfect, but they did the best they could.

Within these traditions and mythologies man, through his inherent knowledge given to him by God, was able to peak at the truth of God in small ways. Thus, ideas such as the virgin birth found their way into their thoughts.

All these ideas come from the One True God. The fullest and most perfect expression of these ideas, however, can only come when God reveals the meaning of such things -- which he did with the Law and Prophets, and most fully through Christ and His Church.

To put it another way, God is the Artist of the Universe. Pagans were able to peak at a small corner of the painting. Since that is all they could see they did the best they could to interpret the painting. Obviously with so little information, they interpreted imperfectly and even outright wrongly. But they did the best they could.

When God brought the Law and the Prophets, He revealed more of the painting to man -- to Israel. Thus, Israel had a more accurate understanding of the painting, but still very limited.

With Christ and His Church God reveal most of His painting to His children. Thus, in Christ, with His Church, we have the most accurate understanding and interpretation of God's painting of the universe. Only in the next life will be see the complete painting and have a perfect understanding.

Hope this helps.

God Bless,
Bro. Ignatius Mary