The Bible records no "thus saith the Lord" concerning birthdays, but two major points emerge from a Bible study on the subject. First, the biblical examples of birthday observances are negative (see Genesis 40:20-22; Matthew 14:6-10). Both involve executions—death. Second, birthday celebrations are fundamentally selfish in that all attention is focused on the self and "getting" presents and congratulations. God, on the other hand, wants us to learn to give, to have outgoing concern, to think of others better than ourselves.
Obviously, the people of the Bible knew their ages, showing that they were at least marking the passage of the years. Therefore, we believe it is not wrong to acknowledge another's birthday with a card or phone call, congratulating the person for having passed another year successfully, much as Herbert Armstrong would send flowers to his mother. However, parties, gifts and excessive praise (especially for children) should be avoided because of the wrong attitudes they teach.