Disobeying what He said is NOT believing in Him. Here is just one example.
He says.
Deuteronomy 12:30 Take heed to thyself that thou be not snared by following them, after that they be destroyed from before thee; and that thou enquire not after their gods, saying, How did these nations serve their gods? even so will I do likewise. 31 Thou shalt not do so unto the LORD thy God
But the Catholic Church says this.
“We need not shrink from admitting that candles, like incense and lustral water, were commonly employed in pagan worship and the rites paid to the dead. But the Church from a very early period took them into her service, just as she adopted many other things indifferent in themselves, which seemed proper to enhance the splendor of religious ceremonial. We must not forget that most of these adjuncts to worship, like music, lights, perfumes, ablutions, floral decorations, canopies, fans, screens, bells, vestments etc. were not identified with any idolatrous cult in particular; but they were common to almost all cults” (Catholic Encyclopedia, III, 246.)
If people believe in Him they don’t do what He said not to.
Jesus prayed that His believers WILL BE ONE: John 17.