If you struggle with intrusive mental images of ANRs, then “think often that Christ suffered agony for your purity. Fight image with image. Christ crying in agony.”
Christ gave Himself for us, that He might redeem us from every lawless deed and purify for Himself a people for His own possession, zealous for good deeds.
1 Peter 1:18; 2:24:
You were not redeemed with perishable things like silver or gold from your futile way of life inherited from your forefathers, [but with the precious blood of Christ]. He Himself bore our sins in His body on the cross, that we might die to sin and live to righteousness; for by His wounds you were healed.
1 Corinthians 5:15:
He died for all, that they who live should no longer live for themselves, but for Him who died and rose again on their behalf.
How much severer punishment do you think he will deserve who has trampled under foot the Son of God, and has regarded as unclean the blood of the covenant by which he was sanctified, and has insulted the Spirit of grace?
From Strategies for Fighting Sexual Sin by John Piper