Mark 4:40 And he said unto them, Why are ye so fearful? how is it that ye have no faith?
Hebrews 3:18-19 And to whom sware he that they should not enter into his rest, but to them that believed not? So we see that they could not enter in because of unbelief.
Psalm 37:5 Commit thy way unto the LORD; trust also in him; and he shall bring it to pass.
Isaiah 26:3 Thou wilt keep him in perfect peace, whose mind is stayed on thee: because he trusteth in thee.