Judges 12-16

Samson had already gotten into trouble with one woman, but now he tried again, this time going deep into enemy territory to Gaza. Again, God warned him by allowing the enemy to almost catch him, but Samson still refused to repent. It was then that Delilah came into his life and led him to his doom.
It shocks us to see this Nazarite sleeping on the lap of a wicked woman, but this is what happens when people choose to go their own way and reject the counsel of loved ones and the Lord. Three times Delilah enticed Samson, and three times he lied to her. Each time, the enemy attacked him, so he should have realized he was in danger.
The rest of the story shows the tragic end of the believer who will not let God have his way with his life. From v. 20 on, Samson does nothing but lose. He loses his hair. Then he loses his strength, but he is ignorant of it until he is overpowered. How futile it is for the servant of God to try to serve the Lord when out of His will. Next Samson loses the light, for the Philistines put out his eyes. He loses his liberty, for they bind him with fetters of brass. He loses his usefulness to the Lord, for he ends up grinding corn instead of fighting God’s battles. Someone has said that v. 21 pictures the blinding, binding, and grinding results of sin. And all of this began when Samson despised his blessings and defied his parents!
Samson also lost his testimony, for he was the laughingstock of the Philistines. Their fish-god Dagon, not the God of Israel, was given all the glory. Apparently Samson repented of his sin, for God gave him one more chance to act by faith. His hair had begun to grow and Samson asked God for strength to win one more victory over the enemy. God answered his prayer, but in defeating others, Samson took his own life.
Samson illustrates people who have power to conquer others, but who cannot conquer themselves. He set the Philistine fields on fire, but could not control the fires of his own lust. He killed a lion, but would not put to death the passions of the flesh. He could easily break the bonds that men put on him, but the shackles of sin gradually grew stronger on his soul. Instead of leading the nation, he preferred to work independently, and as a result, left no permanent victory behind. He was remembered for what he destroyed, not for what he built up. He lacked discipline and direction; without these, his strength could accomplish little. He failed to check the impulses that began early in his career, and twenty years later, they killed him.
It remained for Samuel and David in later years to finally defeat the Philistines. Samuel by one prayer accomplished more than Samson did in twenty years of fighting. (see 1 Sam. 7:9–14). Wiersbe