Rule of faith or the standard for believing the truth!
we have nothing else? Really?
what about Jesus Christ?
Jn 1:17 For the law was given by Moses, but grace and truth came by Jesus Christ.
What about the church?
Matt 18:17 And if he shall neglect to hear them, tell it unto the church: but if he neglect to hear the church, let him be unto thee as an heathen man and a publican.
1 Timothy 3:15
But if I tarry long, that thou mayest know how thou oughtest to behave thyself in the house of God, which is the church of the living God, the pillar and ground of the truth.
what about tradition, that which is handed down? 2 thes 2:15 Therefore, brethren, stand fast, and hold the traditions which ye have been taught, whether by word, or our epistle
even the heavens proclaim the glory of God! Psalm 19:1 The heavens declare the glory of God;
The rule faith is God, and His divine revelation!