1 John 2:19

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

Acts 20:30

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

1 Corinthians 11:19

for there must also be factions among you, that the approved may be made manifest among you.

Matthew 13:20-21

And he that was sown on the rocky places, this is he who hears the word, and straightway with joy receives it;

Matthew 24:24

for there will arise false Christs and false prophets; and they will give great signs and wonders, so as to lead astray, if possible, even the elect.

Mark 4:5-6

And other fell on the rocky ground where it had not much earth; and straightway it sprang up, because of not having depth of earth;

Mark 4:16-17

And these likewise are those sown upon the rocky places, who, when they hear the word, straightway with joy receive it;

Mark 13:22

for there will arise false Christs and false prophets, and will show signs and wonders, in order to lead astray, if possible, the elect.

Luke 8:13

"And those on the rock are those who, when they hear, receive the word with joy; and these have no root; who, for a season, believe, and in time of temptation fall away.

John 4:14

but whosoever drinks of the water that I will give him will never thirst; but the water that I will give him will become in him a well of water springing up into eternal life."

John 6:37-39

All that the Father giveth to Me shall come to Me; and him who comes to Me I will in no wise cast out;

John 10:28-30

and I give to them eternal life; and they shall never perish, nor shall any one snatch them out of My hand.

John 15:2

Every branch in Me that bears not fruit, He taketh it away: and every one that bears fruit, He cleanseth it, that it may bear more fruit.

Acts 15:24

Forasmuch as we heard that some from among us troubled you with words, unsettling your souls??o whom we gave no directions;

Romans 9:6

But it is not as though the word of God has failed: for they are not all Israel, who are of Israel;

Romans 11:5-6

Even so, then, at this present time also, a remnant, according to an election of grace, has been reserved.

2 Timothy 2:10

Therefore, I suffer all things for the sake of the elect, that they also may obtain the salvation which is in Christ Jesus, with eternal glory.

2 Timothy 2:19

Nevertheless, the firm foundation of God has been standing, having this seal, "The Lord knew those who are His:" and "Let every one who names the name of the Lord depart from unrighteousness."

2 Timothy 3:9

But they will proceed no further; for their folly will be fully manifest to all, as theirs also became.

Hebrews 10:39

But we are not of those who draw back to destruction; but of those who believe to the saving of the soul.

1 Peter 1:2-5

elect according to the fore-knowledge of God the Father, in sanctification of the Spirit, unto obedience and sprinkling of the blood of Jesus Christ: grace to you, and peace be multiplied.

2 Peter 2:20-21

For if, after having escaped the defilements of the world in a full knowledge of our Lord and Savior Jesus Christ, but, having again become entangled with these, they are overcome, the last state has become worse with them than the first.

Jude 1:1

Jude, a slave of Jesus Christ, and brother of James, to the called, beloved in God the Father, and kept for Jesus Christ:

Jude 1:19

These are those who make separations; 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
And he that was sown on the rocky places, this is he who hears the word, and straightway with joy receives it;
Mark 4:5
And other fell on the rocky ground where it had not much earth; and straightway it sprang up, because of not having depth of earth;
Luke 8:13
"And those on the rock are those who, when they hear, receive the word with joy; and these have no root; who, for a season, believe, and in time of temptation fall away.
John 15:2
Every branch in Me that bears not fruit, He taketh it away: and every one that bears fruit, He cleanseth it, that it may bear more fruit.
Acts 15:24
Forasmuch as we heard that some from among us troubled you with words, unsettling your souls??o whom we gave no directions;
Acts 20:30
and from among yourselves will men arise, speaking perverse things, to draw away the disciples after them.
2 Peter 2:20
For if, after having escaped the defilements of the world in a full knowledge of our Lord and Savior Jesus Christ, but, having again become entangled with these, they are overcome, the last state has become worse with them than the first.
Jude 1:19
These are those who make separations; sensual, having not the Spirit.

They might

Romans 9:6
But it is not as though the word of God has failed: for they are not all Israel, who are of Israel;
Romans 11:5
Even so, then, at this present time also, a remnant, according to an election of grace, has been reserved.
1 Corinthians 11:19
for there must also be factions among you, that the approved may be made manifest among you.
2 Timothy 3:9
But they will proceed no further; for their folly will be fully manifest to all, as theirs also became.
Hebrews 10:39
But we are not of those who draw back to destruction; but of those who believe 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 in no wise follow, but will flee from him; because they know not the voice of strangers."
1 Timothy 5:15
for already some turned aside after Satan.