Does following the Bible alone makes a bad christian out of me? Isnt being inspired by the exemple of Jesus Christ as explained in the Évangiles enough for me? What does the Chatolic Church do to justify is existance?
I'll be brief and go into more depth on anything you wish. The first part, Nuts' answer is the best there is, it's a matter between you and God whether or not you are a good Christian.
I really don't know what Évangiles translates to, but from what I tried to find it related to the Bible. If you're asking why isn't following the Bible enough, it's because the Church doesn't teach sola scriptura, meaning that it does not teach that the all Bible does not teach all theological truths. Both Catholics, against sola scriptura, and Protestants, for sola scriptura, claim that their position is supported by the Bible.
As for the the justification for the existence of the Church, it starts from the quote "I also say to you that you are Peter, and upon this rock I will build My church; and the gates of Hades will not overpower it" (Matt 16:17-19). Why does it exist to this day? It's due to apostolic succession meaning that every heir back to Peter can be traced. Catholics interpret the Bible to support this notion and Protestants to denounce it. Plus the quotes such as "no prophecy of scripture is a matter of one’s own interpretation" (2 Peter 1:21) and "there are some things in them hard to understand, which the ignorant and unstable twist to their own destruction, as they do the other scriptures" (2 Peter 3:16).
B~E said:
Does that mean that christians have to follow all 613 judaic laws? If not, how do you justify the separation of the New and Ancient Testament?
It does not.
"For if that first covenant had been faultless, there would have been no occasion sought for a second. For finding fault with them, He says,
"BEHOLD, DAYS ARE COMING, SAYS THE LORD,
WHEN I WILL EFFECT A NEW COVENANT
WITH THE HOUSE OF ISRAEL AND WITH THE HOUSE OF JUDAH;
NOT LIKE THE COVENANT WHICH I MADE WITH THEIR FATHERS
ON THE DAY WHEN I TOOK THEM BY THE HAND
TO LEAD THEM OUT OF THE LAND OF EGYPT;
FOR THEY DID NOT CONTINUE IN MY COVENANT,
AND I DID NOT CARE FOR THEM, SAYS THE LORD.
FOR THIS IS THE COVENANT THAT I WILL MAKE WITH THE HOUSE OF ISRAEL
AFTER THOSE DAYS, SAYS THE LORD:
I WILL PUT MY LAWS INTO THEIR MINDS,
AND I WILL WRITE THEM ON THEIR HEARTS.
AND I WILL BE THEIR GOD,
AND THEY SHALL BE MY PEOPLE.
AND THEY SHALL NOT TEACH EVERYONE HIS FELLOW CITIZEN,
AND EVERYONE HIS BROTHER, SAYING, 'KNOW THE LORD,'
FOR ALL WILL KNOW ME,
FROM THE LEAST TO THE GREATEST OF THEM.
FOR I WILL BE MERCIFUL TO THEIR INIQUITIES,
AND I WILL REMEMBER THEIR SINS NO MORE."
When He said, "A new covenant," He has made the first obsolete But whatever is becoming obsolete and growing old is ready to disappear. " (Hebrews 8:7-13)
(the all caps is how it is in the Bible, I mean no emphasis to that part)