The intentions of people will not come to fruition if it is against God’s purpose or plan.  Being in God’s will is to ask Him, seek Him and seek His will.  Many people did not seek or ask God for His will after the flood.

After people had migrated to the plain of Shinar…
(NASB) Genesis 11:3- “They said to one another, ‘Come, let us make bricks and burn them thoroughly.’  And they used brick for stone, and they used tar for mortar.
4 They said, ‘Come, let us build for ourselves a city, and a tower whose top will reach into heaven, and let us make for ourselves a name, otherwise we will be scattered abroad over the face of the whole earth.’
(Underlining added)

The ways of those people seemed right in their own eyes…noble even…but their motives were to glorify themselves…to “make a name” for themselves.
(NIV) Proverbs 16:2 “All a man’s ways seem innocent to him,
But the motives are weighed by the LORD.”

The LORD is all-powerful, Sovereign and He is the Creator…He created languages…for people to speak…amazing isn’t it?
(NASB) Genesis 11:5-9 “The LORD came down to see the city and the tower which the sons of men had built.
6 The LORD said, ‘Behold, they are one people, and they all have the same language.  And this is what they began to do, and now nothing which they purpose to do will be impossible for them.
7 ‘Come, let Us go down and there confuse their language, so that they will not understand one another’s speech.’
8 So the LORD scattered them abroad from there over the face of the whole earth; and they stopped building the city.
9 Therefore its name was called Babel, because there the LORD confused the language of the whole earth; and from there the LORD scattered them abroad over the face of the whole earth.”
(Underlining added)

God’s “let Us” is all-powerful…people’s “let us” sounds good but lacks the power to usurp God’s authoritative power.

When you pray, do you pray for God’s will to be done on earth as it is in heaven?
(NASB) Proverbs 16:3 “Commit your works to the LORD
And your plans will be established.”