Yes, Jesus is the Word. Yes, Jesus is the Way, Yes, Jesus is the only truth for Catholics.
Not a custom — the truth.
JESUS IS THE WORD and HIS TRUTH is not the final authority for those with man made teachings. So it is double speak to say it's the only truth for catholics for they have 'another' truth.
'A double minded man is unstable is all his ways'. James 1:8
Their loyalty is divided between God and the world, and they are unstable in everything they do.
No one can serve two masters.
God's WORD is The Final Authority.