1 Corinthians 8:12

But if you sin in this way against the brethren, and wound their weak conscience, you sin against Christ.

Matthew 25:45

Then will he answer them, saying: Verily I say to you, Inasmuch as you did it not to one of the least of these, you did it not to me.

Matthew 18:6

but whoever ensnares one of these little ones that believe in me, it were better for him that a millstone were hung about his neck, and that he were drowned in the depth of the sea.

Matthew 12:49-50

And he stretched out his hand toward his disciples, and said: Behold my mother and my brothers.

Matthew 18:10

Take heed that you despise not one of these little ones: for I say to you, That their angels in heaven do always behold the face of my Father who is in heaven.

Matthew 18:21

Then Peter came to him, and said: Lord, how often shall my brother sin against me, and I forgive him? Till seven times?

Matthew 25:40

And the King will answer and say to them: Verily I say to you, Inasmuch as you did it to one of the least of these my brethren, you did it to me.

Acts 9:4-5

And when he had fallen to the earth, he heard a voice saying to him: Saul, Saul, why do you persecute me?

1 Corinthians 12:12

For as the body is one, and has many members, and all the members of the body, being many, are one body, so also is the Christ.

Treasury of Scripture Knowledge

Summary

But when ye sin so against the brethren, and wound their weak conscience, ye sin against Christ.

Bible References

When

Matthew 18:21
Then Peter came to him, and said: Lord, how often shall my brother sin against me, and I forgive him? Till seven times?

Ye sin against

1 Corinthians 12:12
For as the body is one, and has many members, and all the members of the body, being many, are one body, so also is the Christ.
Matthew 12:49
And he stretched out his hand toward his disciples, and said: Behold my mother and my brothers.
Matthew 18:10
Take heed that you despise not one of these little ones: for I say to you, That their angels in heaven do always behold the face of my Father who is in heaven.
Matthew 25:40
And the King will answer and say to them: Verily I say to you, Inasmuch as you did it to one of the least of these my brethren, you did it to me.
Acts 9:4
And when he had fallen to the earth, he heard a voice saying to him: Saul, Saul, why do you persecute me?

General references

2 Corinthians 6:3
for we put no stumbling-block in any man's way, in order that this ministry may not be blamed;
Galatians 2:18
For if I build again those things which I have destroyed, I make myself a transgressor.
Philippians 2:4
Consider not each one his own gifts, but each one also the gifts of others.