New Revised Standard Version
and said, “Truly I tell you, unless you change and become like children, you will never enter the kingdom of heaven.

Contemporary English Version
Then he said: I promise you this. If you don't change and become like a child, you will never get into the kingdom of heaven.

New American Bible
and said, “Amen, I say to you, unless you turn and become like children, you will not enter the kingdom of heaven.

Douay-Rheims Bible
And said: amen I say to you, unless you be converted, and become as little children, you shall not enter into the kingdom of heaven.

And said: amen I say to you, unless you be converted, and become as little children, you shall not enter into the kingdom of heaven.

Verily.

Matthew 5:18 For amen I say unto you, till heaven and earth pass, one jot, or one tittle shall not pass of the law, till all be fulfilled.

Matthew 6:2,5,16 Therefore when thou dost an alms-deed, sound not a trumpet before thee, as the hypocrites do in the synagogues and in the streets, that they may be honoured by men. Amen I say to you, they have received their reward. . . .

John 1:51 And he saith to him: Amen, amen, I say to you, you 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 to him: Amen, amen, I say to thee, unless a man be born again, he cannot see the kingdom of God.

Except.

Matthew 13:15 For the heart of this people is grown gross, and with their ears they have been dull of hearing, and their eyes they have shut: lest at any time they should see with their eyes, and hear with their ears, and understand with their heart, and be converted, and I should heal them.

Psalm 51:10-13 Create a clean heart in me, O God: and renew a right spirit within my bowels. . . .

Psalm 131:2 If I was not humbly minded, but exalted my soul: As a child that is weaned is towards his mother, so reward in my soul.

Isaiah 6:10 Blind the heart of this people, and make their ears heavy, and shut their eyes: lest they see with their eyes, and hear with their ears, and understand with their heart, and be converted and I heal them.

Mark 4:12 That seeing they may see, and not perceive; and hearing they may hear, and not understand; lest at any time they should be converted, and their sins should be forgiven them.

Luke 22:32 But I have prayed for thee, that thy faith fail not: and thou, being once converted, confirm thy brethren.

Acts 3:19 Be penitent, therefore, and be converted, that your sins may be blotted out.

Acts 28:27 For the heart of this people is grown gross, and with their ears have they heard heavily and their eyes they have shut, lest perhaps 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.

James 5:19,20 My brethren, if any of you err from the truth and one convert him: . . .

and become.

Mark 10:14,15 Whom when Jesus saw, he was much displeased and saith to them: Suffer the little children to come unto me and forbid them not: for of such is the kingdom of God. . . .

Luke 18:16,17 But Jesus, calling them together, said: Suffer children to come to me and forbid them not: for of such is the kingdom of God. . . .

1 Corinthians 14:20 Brethren, do not become children in sense. But in malice be children: and in sense be perfect.

1 Peter 2:2 As newborn babes, desire the rational milk without guile, that thereby you may grow unto salvation:

enter.

Matthew 5:20 For I tell you, that unless your justice abound more than that of the scribes and Pharisees, you shall not enter into the kingdom of heaven.

Matthew 19:23 Then Jesus said to his disciples: Amen, I say to you, that a rich man shall hardly enter into the kingdom of heaven.

Luke 13:24 Strive to enter by the narrow gate: for many, I say to you, shall seek to enter and shall not be able.

John 3:5 Jesus answered: Amen, amen, I say to thee, unless a man be born again of water and the Holy Ghost, he cannot enter into the kingdom of God.

Acts 14:22 Confirming the souls of the disciples and exhorting them to continue in the faith: and that through many tribulations we must enter into the kingdom of God.

2 Peter 1:11 For so an entrance shall be ministered to you abundantly into the ever-lasting kingdom of our Lord and Saviour Jesus Christ.