Christianity failed Christ Jesus teaching, Islam failed it too, Now there is Bahai, it may work.
I would agree, if you put Christianity in quotation marks, since Christianity which Jesus' followers practiced, is still being practiced today.
So it is important to differentiate, because since the early (first century) Christians did not fail Christ's teachings, and there are indeed persons today practicing the same creeds as first century Christians.
Would you not agree?
To give just a few examples...
1. The first century Christians were no part of the world - they did not get involved in politics, and wars, etc. John 15:17-19 ; 1 John 2:15-17
2. They engaged in the work of making disciples - preaching the good news of God's kingdom from town to town, village to village to the most distant part of the world. Just look at the Acts of the apostles, and their travels, as well as when they accompanied Jesus on his preaching campaigns.
You would notice too, that they were travelling overseers sent by the body in Jerusalem, to build up newly formed congregation of new disciples, and to appoint overseers in each congregation.
Note also, that all new disciples engaged in the same work of preaching the good news, with their fellow brothers. Matthew 24:14 ; 28:19, 20 ; Luke 8, 9, 10
3. They had love among themselves, and this was seen from their sharing all things in common with one another.
They took care of their elderly and widows, as well as orphans.
They came to the aid of those in need, by arranging for supplies to be sent through the hands of the brothers. John 15:35 ; 1 Corinthians 1:10 ; 2 Corinthians 13:11
4. They were united by divine teaching, and were not divided in scriptural teachings, no matter which part of the earth they lived.
This due to their being fed by one "slave" / "servant". Matthew 24:45
These are just a few areas where first century Christian practices are carried out today.
Do you see anyone doing these things?