A great place to look to find a quote that supports this important theme in the play is at the end of Act I, when Abigail is accused of witchery and then she turns on Tituba, who then turns on others in turn, supported by the girls. A key aspect of the Salem witch trials, which is actually incredibly disturbing, is the way that to save yourself you were expected to turn others in. This of course produced a massive growth in the supposed cases of witchery. To not accuse others was tantamount to signing your own death warrant, as John Proctor and others discover.
Note the way that when Tituba is brought in, Abigail straight away accuses her: "She made me do it! She made Betty do it!" Abigail turns on Tituba to deflect the focus on her own misdeeds. As she sees the success of her allegations, Abigail continues to accuse Tituba of other things:
She comes to me every night to go and drink blood! ... She comes to me while I sleep; she's always making me dream corruptions! ... Somestimes I wake and find myself standing in the open doorway and not a stitch on my body! I always hear her laughing in my sleep. I hear her singing her Barbados songs and tempting me with--
This of course forces Tituba to confess herself, and then, Abigail, ever the opportunist, again declares her own guilt in witchcraft, realising clearly the kind of power that being able to denounce others would give her:
I want to open myself! I want the light of God, I want the sweet love of Jesus! I danced for the devil; I saw him; I wrote in his book; I go back to Jesus; I kiss His hand. I saw Sarah Good with the Devil! I saw Goody Osburn with the Devil! I saw Bridget bishop with the Devil!
It is this power to denounce others and to accuse them of witchery that Abigail embraces by her confession of witchery, and it is this power as well that allows her to save herself and prevent the very uncertain future that faces her otherwise.