“Let the word of Christ dwell in you richly in all wisdom, teaching and admonishing one another in psalms and hymns and spiritual songs, singing with grace in your hearts to the Lord.” Colossians 3:16.
“The heart is deceitful above all things, and desperately wicked; who can know it? I, the Lord, search the heart, I test the mind, even to give every man according to his ways, and according to the fruit of his doings.” Jeremiah 17:9-10.
“And again He began to teach by the sea. And a great multitude was gathered to Him, so that He got into a boat and sat in it on the sea; and the whole multitude was on the land facing the sea. Then He taught them many things by parables, and said to them in His teaching: ‘Listen! Behold, a sower went out to sow. And it happened, as he sowed, that some seed fell by the wayside; and the birds of the air came and devoured it. Some fell on stony ground, where it did not have much earth; and immediately it sprang up because it had no depth of earth. But when the sun was up it was scorched, and because it had no root it withered away. And some seed fell among thorns; and the thorns grew up and choked it, and it yielded no crop. But other seed fell on good ground and yielded crop that sprang up, increased and produced: some thirtyfold, some sixty, and some a hundred.’ And He said to them, ‘He who has ears to hear, let him hear!’” Mark 4:1-9.
“My brethren, let not many of you become teachers, knowing that we shall receive a stricter judgment. For we all stumble in many things. If anyone does not stumble in word, he is a perfect man, able also to bridle the whole body.” James 3:1-2.