"Just as it pleased the LORD to make you prosper and increase in number, so it will please him to ruin and destroy you. You will be uprooted from the land you are entering to possess" (Deuteronomy 28:63).
"Therefore God has mercy on whom he wants to have mercy, and he hardens whom he wants to harden" (Rom 9:18).
"For this reason God sends them a powerful delusion so that they will believe the lie" (2 Thessalonians 2:11).
"He has blinded their eyes and hardened their hearts, so they can neither see with their eyes, nor understand with their hearts, nor turn-and I would heal them" (John 12:39-40)
"For it was the LORD himself who hardened their hearts to wage war against Israel, so that he might destroy them totally, exterminating them without mercy, as the LORD had commanded Moses." (Joshua 11:20).
"... for it was the LORD's will to put them to death" (1 Samuel 2:25).
and on the other hand there are the verses that speak to God's will to save men from sin and death.
"This is good, and pleases God our Savior, who wants all men to be saved and to come to a knowledge of the truth" (1 Timothy 2:3-4).
"For God so loved the world that he gave his only son, that whomever believes in him shall not perish, but shall have everlasting life" (John 3:16).
"O Jerusalem, Jerusalem, you who kill the prophets and stone those sent to you, how often I have longed to gather your children together, as a hen gathers her chicks under her wings, but you were not willing." (Matthew 27:37)
"Do I take any pleasure in the death of the wicked? declares the Sovereign LORD. Rather, am I not pleased when they turn from their ways and live?" (Ezekiel 18:23)
I think the best way to reconcile the passages is to see the difference not between two equal and opposite wills, but as one set expressing the character of God and the other recording his actions. When presented this way there's no conflict between them (in fact you need both together to understand Him properly).
Say for a moment we had insight into the first set of verses describing Gods actions but not the second set describing His character. In that case we would see Him damning the wicked and withholding mercy, and we'd think Him cruel and unapproachable. On the other hand if we only had the verses describing His soft character He would appear to us to be a weak powerless God, if even a God at all.
The difference in Scripture then is not so much between His permissive, persuasive, effectual, continual will, but the between His nature and His decrees. His feelings and His actions. Together they paint the complete picture, showing us not only what He does for His glory, but why.