We hold the faith which is common to all the believers
(Titus 1:4; Jude 3):

Titus 1:4
To Titus, genuine child according to the common faith: Grace and peace from God the Father and Christ Jesus our Savior.

Jude 3
Beloved, while using all diligence to write to you concerning our common salvation, I found it necessary to write to you and exhort you to earnestly contend for the faith once for all delivered to the saints.