Matthew 18:3

and said, I declare to you, except ye lay aside your ambition, and become as children, ye shall not enter into the kingdom of the Messias.

Mark 10:14-15

which Jesus observing was much displeas'd with them, and said, suffer little children to come unto me, do not hinder them: for of such is the kingdom of God.

1 Peter 2:2

which is without any mixture, and will make you thrive. Since you have tasted how good the Lord is,

1 Corinthians 14:20

Brethren, be not childish in understanding: be as innocent as babes, but use your understanding like men.

Matthew 19:14

but Jesus said, let the children alone, and don't hinder them from coming to me: for of such does the gospel-kingdom consist.

Matthew 5:20

for I declare to you, that except your righteousness shall exceed that of the Scribes and Pharisees, ye shall not enter into the heavenly kingdom.

Luke 18:16-17

but Jesus called the children to him, and said to his disciples, let the children come to me, without any hindrance, for they who belong to the kingdom of God, must be like them.

Luke 22:32

but as for thee, I have pray'd that you faith may not fail. do you in return establish thy brethren.

Matthew 5:18

I assure you, heaven and earth may as well cease to be, as that one jot or one tittle of the law should fail of its completion.

Matthew 6:2

therefore, when you give alms, do not make a proclamation of it as the hypocrites do, in their publick assemblies by sound of trumpet, that they may have the applause of men. for I assure you, they have their reward.

Matthew 6:5

And when you pray, be not as the hypocrites are: for they chuse to stand praying in publick places, and at the corners of the streets, to be observ'd by men. I assure you, they have their reward.

Matthew 6:16

When ye fast, don't put on a dismal air, as the hypocrites do, who look dejected, that men may take notice of their fasting: I assure you, they have their reward.

Matthew 13:15

for the heart of this people is waxed gross, and their ears are dull of hearing, and their eyes they have closed; lest at any time they should see with their eyes, and hear with their ears, and understand with their heart, and should be converted, and I should heal them."

Matthew 19:23

then said Jesus to his disciples, I declare unto you, it will be difficult for a rich man to enter into the gospel kingdom.

Mark 4:12

tho' they see, they will not perceive, and tho' they hear they will not understand: as if they were afraid of parting with their vices, in order to be pardoned.

Luke 13:24

strive to enter in at the narrow gate: for I declare unto you, that many shall try to get in, and shall not be able.

John 1:51

and he said to him, I declare unto you, hereafter you shall see heaven open, and the angels of God ascending, and descending upon the son of man.

John 3:3

Jesus answered him, I declare unto thee, except a man be born again, he cannot see the kingdom of God.

John 3:5

Jesus answered, I tell thee, except a man be renewed by the spiritual baptism, he cannot enter into the kingdom of God.

Acts 3:19

repent therefore, and be converted, that your sins may be blotted out, when the times of refreshment shall come from the presence of the Lord, who shall send Jesus Christ,

Acts 14:22

encouraging the disciples, exhorting them to persevere in the faith, representing that it is thro' much tribulation that we must enter into the kingdom of God.

Acts 28:27

for the heart of this people is become gross, their ears are dull of hearing, and their eyes have they closed; lest they should see with their eyes, and hear with their ears, and understand with their heart, and be converted and I should heal them."

James 5:19-20

My brethren, when any of you deviates from the truth, whoever sets him right, may be assured,

2 Peter 1:11

and thus you will have a free admittance 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
which Jesus observing was much displeas'd with them, and said, suffer little children to come unto me, do not hinder them: for of such is the kingdom of God.
Luke 18:16
but Jesus called the children to him, and said to his disciples, let the children come to me, without any hindrance, for they who belong to the kingdom of God, must be like them.
1 Corinthians 14:20
Brethren, be not childish in understanding: be as innocent as babes, but use your understanding like men.
1 Peter 2:2
which is without any mixture, and will make you thrive. Since you have tasted how good the Lord is,

General references

Mark 10:15
I declare unto you, he that shall pretend to be admitted into the kingdom of God, and has not the temper of a little child, shall not enter therein.
Luke 9:46
At length they enter'd into a debate, which of them should be the greatest.
Luke 22:26
but you must not be such: the greatest of you must be as the junior, and he that governs as he that serves.
Acts 8:19
give me too this power, that on whomsoever I lay hands he may receive the holy spirit.