New Revised Standard Version
For the gate is narrow and the road is hard that leads to life, and there are few who find it.

Contemporary English Version
But the gate to life is very narrow. The road that leads there is so hard to follow that only a few people find it.

New American Bible
How narrow the gate and constricted the road that leads to life. And those who find it are few.

Douay-Rheims Bible
How narrow is the gate, and strait is the way that leadeth to life: and few there are that find it!

How narrow is the gate, and strait is the way that leadeth to life: and few there are that find it!

because.

Matthew 16:24,25 Then Jesus said to his disciples: If any man will come after me, let him deny himself, and take up his cross, and follow me. . . .

Proverbs 4:26,27 Decline not to the right hand, nor to the left: turn away thy foot from evil. For the Lord knoweth the ways that are on the right hand: but those are perverse which are on the left hand. But he will make thy courses straight, he will bring forward thy ways in peace. . . .

Proverbs 8:20 That I may enrich them that love me, and may fill their treasures.

Isaiah 30:21 And thy ears shall hear the word of one admonishing thee behind thy back: This is the way, walk ye in it: and go not aside neither to the right hand, nor to the left.

Isaiah 35:8 And a path and a way shall be there, and it shall be called the holy way: the unclean shall not pass over it, and this shall be unto you a straight way, so that fools shall not err therein.

Isaiah 57:14 And I will say: Make a way: give free passage, turn out of the path, take away the stumblingblocks out of the way of my people.

Jeremiah 6:16 Thus saith the Lord: Stand ye on the ways, and see, and ask for the old paths, which is the good way, and walk ye in it: and you shall find refreshment for your souls. And they said: We will not walk.

Mark 8:34 And calling the multitude together with his disciples, he said to them: If any man will follow me, let him deny himself and take up his cross and follow me.

John 15:18-20 If the world hate you, know ye that it hath hated me before you. . . .

John 16:2,33 They will put you out of the synagogues: yea, the hour cometh, that whosoever killeth you will think that he doth a service to 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.

1 Thessalonians 3:2-5 And we sent Timothy, our brother and the minister of God in the gospel of Christ, to confirm you and exhort you concerning your faith: . . .

and few.

Matthew 20:16 So shall the last be first and the first last. For many are called but few chosen.

Matthew 22:14 For many are called, but few are chosen.

Matthew 25:1-12 Then shall the kingdom of heaven be like to ten virgins, who taking their lamps went out to meet the bridegroom and the bride. . . .

Luke 12:32 Fear not, little flock, for it hath pleased your Father to give you a kingdom.

Luke 13:23-30 And a certain man said to him: Lord, are they few that are saved? But he said to them: . . .

Romans 9:27-29,32 And Isaias cried out concerning Israel: If the number of the children of Israel be as the sand of the sea, a remnant shall be saved. . . .

Romans 11:5,6 Even so then, at this present time also, there is a remnant saved according to the election of grace. . . .

Romans 12:2 And be not conformed to this world: but be reformed in the newness of your mind, that you may prove what is the good and the acceptable and the perfect will of God.

Ephesians 2:2,3 Wherein in time past you walked according to the course of this world, according to the prince of the power of this air, of the spirit that now worketh on the children of unbelief: . . .

1 Peter 3:20,21 Which had been some time incredulous, when they waited for the patience of God in the days of Noe, when the ark was a building: wherein a few, that is, eight souls, were saved by water. . . .