And, The truth,that non-Catholics have trouble accepting is that it is not, nor has it ever been the ONLY source.
“Whoever revolteth, and continueth not in the doctrine of Christ, hath not God.”—2 John 1:9 DR
The “doctrine of Christ” is laid out in the apostles’ letters...which God inspired them to write and made sure we have today. Wherefore you have no excuse for disregarding them in favor of fanciful additions.