“And to the angel of the church in Sardis write, ‘These things says He who has the seven Spirits of God and the seven stars: ‘I know your works, that you have a name that you are alive, but you are dead. Be watchful, and strengthen the things which remain, that are ready to die, for I have not found your works perfect [finished or complete] before God. Remember therefore how you have received and heard; hold fast and repent. Therefore if you will not watch, I will come upon you as a thief, and you will not know what hour I will come upon you.’” Revelation 3:1-3.
“And whoever receives one little child like this in My name receives Me. But whoever causes one of these little ones who believe in Me to sin, it would be better for him if a millstone were hung around his neck, and he were drowned in the depth of the sea.” Matthew 18:5-6.