Nobody claimed it was.
But the Bible alone is sufficient to explain the path to salvation, in that it points us to Jesus, and CLEARLY explains that "For it is by grace you have been saved, through faith—and this is not from yourselves, it is the gift of God— not by works, so that no one can boast. Eph 2:8-9
Salvation is not gained through your church membership, rather, you become a member of Christ's church when you are born again!
How does one become born again?