Matthew 18:3

and said, Verily I say unto you, Except ye turn, and become as little children, ye shall in no wise enter into the kingdom of heaven.

Mark 10:14-15

But when Jesus saw it, he was moved with indignation, and said unto them, Suffer the little children to come unto me; forbid them not: for to such belongeth the kingdom of God.

1 Peter 2:2

as newborn babes, long for the spiritual milk which is without guile, that ye may grow thereby unto salvation;

1 Corinthians 14:20

Brethren, be not children in mind: yet in malice be ye babes, but in mind be men.

Matthew 19:14

But Jesus said, Suffer the little children, and forbid them not, to come unto me: for to such belongeth the kingdom of heaven.

Psalm 131:2

Surely I have stilled and quieted my soul; Like a weaned child with his mother, Like a weaned child is my soul within me.

Matthew 5:20

For I say unto you, that except your righteousness shall exceed the righteousness of the scribes and Pharisees, ye shall in no wise enter into the kingdom of heaven.

Luke 18:16-17

But Jesus called them unto him, saying, Suffer the little children to come unto me, and forbid them not: for to such belongeth the kingdom of God.

Luke 22:32

but I made supplication for thee, that thy faith fail not; and do thou, when once thou hast turned again, establish thy brethren.

Psalm 51:10-13

Create in me a clean heart, O God; And renew a right spirit within me.

Isaiah 6:10

Make the heart of this people fat, and make their ears heavy, and shut their eyes; lest they sea with their eyes, and hear with their ears, and understand with their heart, and turn again, and be healed.

Matthew 5:18

For verily I say unto you, Till heaven and earth pass away, one jot or one tittle shall in no wise pass away from the law, till all things be accomplished.

Matthew 6:2

When therefore thou doest alms, sound not a trumpet before thee, as the hypocrites do in the synagogues and in the streets, that they may have glory of men. Verily I say unto you, They have received their reward.

Matthew 6:5

And when ye pray, ye shall not be as the hypocrites: for they love to stand and pray in the synagogues and in the corners of the streets, that they may be seen of men. Verily I say unto you, They have received their reward.

Matthew 6:16

Moreover when ye fast, be not, as the hypocrites, of a sad countenance: for they disfigure their faces, that they may be seen of men to fast. Verily I say unto you, They have received their reward.

Matthew 13:15

For this people's heart is waxed gross, And their ears are dull of hearing, And their eyes they have closed; Lest haply they should perceive with their eyes, And hear with their ears, And understand with their heart, And should turn again, And I should heal them.

Matthew 19:23

And Jesus said unto his disciples, Verily I say unto you, It is hard for a rich man to enter into the kingdom of heaven.

Mark 4:12

that seeing they may see, and not perceive; and hearing they may hear, and not understand; lest haply they should turn again, and it should be forgiven them.

Luke 13:24

Strive to enter in by the narrow door: for many, I say unto you, shall seek to enter in, and shall not be able.

John 1:51

And he saith unto him, Verily, verily, I say unto you, Ye shall see the heaven opened, and the angels of God ascending and descending upon the Son of man.

John 3:3

Jesus answered and said unto him, Verily, verily, I say unto thee, Except one be born anew, he cannot see the kingdom of God.

John 3:5

Jesus answered, Verily, verily, I say unto thee, Except one be born of water and the Spirit, he cannot enter into the kingdom of God!

Acts 3:19

Repent ye therefore, and turn again, that your sins may be blotted out, that so there may come seasons of refreshing from the presence of the Lord;

Acts 14:22

confirming the souls of the disciples, exhorting them to continue in the faith, and that through many tribulations we must enter into the kingdom of God.

Acts 28:27

For this people's heart is waxed gross, And their ears are dull of hearing, And their eyes they have closed; Lest, haply they should perceive with their eyes, And hear with their ears, And understand with their heart, And should turn again, And I should heal them.

James 5:19-20

My brethren, if any among you err from the truth, and one convert him;

2 Peter 1:11

for thus shall be richly supplied unto you the entrance into the eternal kingdom of our Lord and Saviour Jesus Christ.

Treasury of Scripture Knowledge

Summary

And said, Verily I say unto you, Except ye be converted, and become as little children, ye shall not enter into the kingdom of heaven.

Bible References

And become

Mark 10:14
But when Jesus saw it, he was moved with indignation, and said unto them, Suffer the little children to come unto me; forbid them not: for to such belongeth the kingdom of God.
Luke 18:16
But Jesus called them unto him, saying, Suffer the little children to come unto me, and forbid them not: for to such belongeth the kingdom of God.
1 Corinthians 14:20
Brethren, be not children in mind: yet in malice be ye babes, but in mind be men.
1 Peter 2:2
as newborn babes, long for the spiritual milk which is without guile, that ye may grow thereby unto salvation;

General references

Mark 10:15
Verily I say unto you, Whosoever shall not receive the kingdom of God as a little child, he shall in no wise enter therein.
Luke 9:46
And there arose a reasoning among them, which of them was the greatest.
Luke 22:26
But ye'shall not be'so: but he that is the greater among you, let him become as the younger; and he that is chief, as he that doth serve.
Acts 8:19
saying, Give me also this power, that on whomsoever I lay my hands, he may receive the Holy Spirit.

American Standard Version Public Domain