A wide range of beliefs and practices is found across the world among those who call themselves Christian. The Nicene creed was established in the 4th century as an expression of Christian faith in the face of heresy .
We believe in one God,
the Father, the Almighty,
of all that is, seen and unseen.
We believe in one Lord, Jesus Christ,
the only Son of God,
eternally begotten of the Father,
God from God, Light from Light,
true God from true God,
begotten, not made,
of one Being with the Father.
Through him all things were made.
For us and for our salvation
he came down from heaven:
by the power of the Holy Spirit
he became incarnate from the Virgin Mary,
and was made man.
For our sake he was crucified under Pontius Pilate;
he suffered death and was buried.
On the third day he rose again
in accordance with the Scriptures;
he ascended into heaven
and is seated at the right hand of the Father.
He will come again in glory to judge the living and the dead,
and his kingdom will have no end.
We believe in the Holy Spirit, the Lord, the giver of life,
who proceeds from the Father and the Son.
With the Father and the Son he is worshipped and glorified.
He has spoken through the Prophets.
We believe in one holy catholic and apostolic Church.
We acknowledge one baptism for the forgiveness of sins.
We look for the resurrection of the dead,
and the life of the world to come. Amen.
Unfortunately many christians nowadays identify themselves as christians but do not really believe in what their doctrine is , it's what we call "cultural christians".
Cultural Christians: Do not view Jesus as essential to salvation. They are the least likely to align their beliefs or practices with biblical teachings or to attend church. They favor a universality theology that sees many ways to God. (Kinds of Christians — Understanding the disparity of those who call themselves Christian in America. Leadership Journal, Fall 2007.)
(Saint Thomas Aquinas, The Angelic Doctor)