These basic prayers should be known by all Christians.
The Lords Prayer
Our Father, who art in heaven, hallowed be thy name, thy kingdom come. Thy will be done on earth as it is in heaven.  Give us this day our daily bread, and forgive us our trespasses, as we forgive those who trespass against us.  And lead us not into temptation, but deliver us from evil.  Amen.
Hail Mary
Hail, Mary, full of grace, the Lord is with thee: blessed art thou among women, and blessed is the fruit of thy womb, Jesus.  Holy Mary, Mother of God, pray for us sinners, now, and at the hour of our death.  Amen.
Glory Be To The Father
Glory be to the Father, and to the Son, and to the Holy Spirit.  As it was in the beginning, is now, and ever shall be, world without end.  Amen
Act of Contrition
O my God, because you are so good, I am very sorry that I have offended you. With the help of your grace I will not sin again. Amen.
 
All Christians should also know how to live.
The 10 Commandments
1. I am the Lord your God, you shall have no false gods before Me.
2. You shall not take the name of the Lord in vain.
3. Keep the Sabbath day holy.
4. Honour your father and mother.
5. You shall not kill.
6. You shall not commit adultery.
7. You shall not steal.
8. You shall not bear false witness against your neighbour.
9. You shall not desire your neighbour's wife.
10. You shall not desire your neighbour's goods.
Precepts of the Church
1.  To keep the Sundays and Holy days of obligation holy, by hearing Mass and resting from servile works.
2.  To keep the days of fasting and abstinence appointed by the Church.
3.  To go to Confession at least once a year.
4.  To receive the Blessed Sacrament at least once a year at Easter or thereabouts
5.  To contribute to the support of your Priests
6.  Not to marry within certain degrees of kindred without dispensation