This is why in the great commission (Matthew 28:18-19) Jesus calls us not to just make Christians, but to make disciples and teach them to obey all that he has taught.
(Jakobe 2:19) Nangabe sifuna kutsi Nkulunkulu asemukele nasimkhonta, kufanele singagcini nje ngekukholwa kutsi ukhona, kepha kufanele sente lasifundzisa kona.