1 John 2:19

They went out from us, but they were not of us; for if they had been of us they would have continued with us; but [they went out from us] that they might be manifest that they are not all of us.

Acts 20:30

and of yourselves men will arise speaking perverse things, to draw away disciples after them.

1 Corinthians 11:19

For it is necessary that there should be heresies among you, that the approved may be manifest among you.

Matthew 13:20-21

He that received seed on the rocky places is he that hears the word and immediately receives it with joy

Matthew 24:24

For false Christs and false prophets shall be raised up, and shall show great signs and wonders, so as to deceive, if possible, even the elect.

Mark 4:5-6

And some fell on a rocky place, where it had not much earth, and it came up immediately, because it had no depth of earth;

Mark 4:16-17

And these in like manner are those sown on the rocky places; when they hear the word, they immediately receive it with joy,

Mark 13:22

For false prophets shall arise, and perform miracles and wonders, to deceive, if possible, the elect.

Luke 8:13

those on the rock are those who, when they hear, receive the word with joy, and they have no root; they believe for a time, and in a time of trial fall away;

John 4:14

but whoever drinks of the water which I will give him shall never thirst; but the water which I will give him shall be in him a fountain of water springing up to eternal life.

John 6:37-39

Every thing which the Father gives to me shall come to me, and him that comes to me I will by no means cast out;

John 10:28-30

and I give them eternal life, and they shall never perish nor shall any one pluck them out of my hand.

John 15:2

Every branch in me that bears not fruit he takes away; and every branch that bears fruit he trims, that it may bear more fruit.

Acts 15:24

Since we heard that some going out from us have troubled you with words subverting your souls, to whom we gave no charge,

Romans 9:6

Not that the word of God has failed of being accomplished. For all are not Israel who are of Israel;

Romans 11:5-6

So then also at the present time there is a remnant according to the election of grace;

2 Timothy 2:10

Therefore I endure all things for the elect, that they may obtain the salvation in Christ Jesus with eternal glory.

2 Timothy 2:19

But the foundation of God stands firm, having this seal, The Lord knows them that are his; and, Let every one who names the name of the Lord depart from wickedness.

2 Timothy 3:9

But they shall proceed no further; for their foolishness shall become manifest to all, as theirs also was.

Hebrews 10:39

But we are not of those who draw back to perdition, but of faith to the saving of the soul.

1 Peter 1:2-5

according to the foreknowledge of God the Father, by sanctification of the Spirit, to obedience and the sprinkling of the blood of Jesus Christ. Grace and peace be multiplied to you.

2 Peter 2:20-21

For if having escaped the defilements of the world by a knowledge of the Lord and Saviour Jesus Christ, they are again entangled and overcome by them, the last state of those persons is worse than the first.

Jude 1:1

JUDAS, a servant of Jesus Christ, and brother of James, to the beloved in God the Father, and the called who are kept by Jesus Christ.

Jude 1:19

These are they who separate themselves, sensual, having not the Spirit.

Treasury of Scripture Knowledge

Summary

They went out from us, but they were not of us; for if they had been of us, they would no doubt have continued with us: but they went out, that they might be made manifest that they were not all of us.

Bible References

Went out

Matthew 13:20
He that received seed on the rocky places is he that hears the word and immediately receives it with joy
Mark 4:5
And some fell on a rocky place, where it had not much earth, and it came up immediately, because it had no depth of earth;
Luke 8:13
those on the rock are those who, when they hear, receive the word with joy, and they have no root; they believe for a time, and in a time of trial fall away;
John 15:2
Every branch in me that bears not fruit he takes away; and every branch that bears fruit he trims, that it may bear more fruit.
Acts 15:24
Since we heard that some going out from us have troubled you with words subverting your souls, to whom we gave no charge,
Acts 20:30
and of yourselves men will arise speaking perverse things, to draw away disciples after them.
2 Peter 2:20
For if having escaped the defilements of the world by a knowledge of the Lord and Saviour Jesus Christ, they are again entangled and overcome by them, the last state of those persons is worse than the first.
Jude 1:19
These are they who separate themselves, sensual, having not the Spirit.

They might

Romans 9:6
Not that the word of God has failed of being accomplished. For all are not Israel who are of Israel;
Romans 11:5
So then also at the present time there is a remnant according to the election of grace;
1 Corinthians 11:19
For it is necessary that there should be heresies among you, that the approved may be manifest among you.
2 Timothy 3:9
But they shall proceed no further; for their foolishness shall become manifest to all, as theirs also was.
Hebrews 10:39
But we are not of those who draw back to perdition, but of faith to the saving of the soul.

General references

Matthew 25:2
and five of them were foolish, and five wise.
John 10:5
But a stranger they will not follow, but will flee from him, for they know not the voice of strangers.
1 Timothy 5:15
for some have already turned back after Satan.