MATTHEW 17:19-20 Then came the disciples to Jesus apart, and said, Why could not we cast him out? And Jesus said unto them, Because of your unbelief: for verily I say unto you, If ye have faith as a grain of mustard seed, ye shall say unto this mountain, Remove hence to yonder place; and it shall remove; and nothing shall be impossible unto you.
MATTHEW 21:21-22 Jesus answered and said unto them, Verily I say unto you, If ye have faith, and doubt not, ye shall not only do this which is done to the fig tree, but also if ye shall say unto this mountain, Be thou removed, and be thou cast into the sea; it shall be done. 22And all things, whatsoever ye shall ask in prayer, believing, ye shall receive.
MATTHEW 21:32 For John came unto you in the way of righteousness, and ye believed him not: but the publicans and the harlots believed him: and ye, when ye had seen it, repented not afterward, that ye might believe him.
MARK 1:14-15 Now after that John was put in prison, Jesus came into Galilee, preaching the gospel of the kingdom of God, And saying, The time is fulfilled, and the kingdom of God is at hand: repent ye, and believe the gospel.
MARK 2:5 When Jesus saw their faith, he said unto the sick of the palsy, Son, thy sins be forgiven thee.
MARK 4:37-40 And there arose a great storm of wind, and the waves beat into the ship, so that it was now full. And he was in the hinder part of the ship, asleep on a pillow: and they awake him, and say unto him, Master, carest thou not that we perish? And he arose, and rebuked the wind, and said unto the sea, Peace, be still. And the wind ceased, and there was a great calm. And he said unto them, Why are ye so fearful? how is it that ye have no faith?
MARK 5:34 And he said unto her, Daughter, thy faith hath made thee whole; go in peace, and be whole of thy plague.
MARK 5:35-43 While he yet spake, there came from the ruler of the synagogue's house certain which said, Thy daughter is dead: why troublest thou the Master any further? As soon as Jesus heard the word that was spoken, he saith unto the ruler of the synagogue, Be not afraid, only believe. And he suffered no man to follow him, save Peter, and James, and John the brother of James. And he cometh to the house of the ruler of the synagogue, and seeth the tumult, and them that wept and wailed greatly. And when he was come in, he saith unto them, Why make ye this ado, and weep? the damsel is not dead, but sleepeth. And they laughed him to scorn. But when he had put them all out, he taketh the father and the mother of the damsel, and them that were with him, and entereth in where the damsel was lying. And he took the damsel by the hand, and said unto her, Talitha cumi; which is, being interpreted, Damsel, I say unto thee, arise. And straightway the damsel arose, and walked; for she was of the age of twelve years. And they were astonished with a great astonishment. And he charged them straitly that no man should know it; and commanded that something should be given her to eat.
MARK 6:3-6 Is not this the carpenter, the son of Mary, the brother of James, and Joses, and of Juda, and Simon? and are not his sisters here with us? And they were offended at him [caused to stumble/sin]. But Jesus said unto them, A prophet is not without honour, but in his own country, and among his own kin, and in his own house. And he could there do no mighty work, save that he laid his hands upon a few sick folk, and healed them. And he marvelled because of their unbelief. And he went round about the villages, teaching.
MARK 9:19-24 He answereth him, and saith, O faithless generation, how long shall I be with you? how long shall I suffer you? bring him unto me. And they brought him unto him: and when he saw him, straightway the spirit tare him; and he fell on the ground, and wallowed foaming. And he asked his father, How long is it ago since this came unto him? And he said, Of a child. And ofttimes it hath cast him into the fire, and into the waters, to destroy him: but if thou canst do any thing, have compassion on us, and help us. Jesus said unto him, If thou canst believe, all things are possible to him that believeth. And straightway the father of the child cried out, and said with tears, Lord, I believe; help thou mine unbelief.