Firmly persuaded that no evil exists in the world that God did not design to take place, I build my belief on the perfection of God. (1.15)
Wollstonecraft refuses to believe that God would have ever made women weak and deceitful by nature. She claims that it's her faith in God that leads her to believe that it's people, and not nature, that make women the way they are.
With respect to religion, she never presumed to judge for herself; but conformed, as a dependent creature should, to the ceremonies of the church which she was brought up in. (3.41)
Many women grow up and never judge the world for themselves. They simply listen to what they're told by their parents and by the church, and they end up never strengthening their judgment.
It is not impious thus to scan the attributes of the Almighty: in fact, who can avoid it that exercises his faculties? (3.29)
For Wollstonecraft, it's not blasphemous to question God's motives, since God gave people the power of reason and He no doubt expects them to use it.
With respect to religion, she never presumed to judge for herself; but conformed, as a dependent creature should, to the ceremonies of the church which she was brought up in, piously believing that wiser heads than her own have settled that business. (3.41)
Again, Wollstonecraft shows us how many women with natural intelligence never end up developing their minds because they obey their parents and the church. They just go through life figuring that all the world's questions have already been answered.
More or less may be conspicuous in one being than another; but the nature of reason must be the same in all, if it be an emanation of divinity, the tie that connects the creature with the Creator. (4.3)
If the power of reason comes directly from God, then it must be the same in all people. In other words, God guarantees that reason has no gender. Therefore, both men and women have the same power of reason and the same ability to strengthen it.
Yet if love be the supreme good, let women only be educated to inspire it […] and let love to man be only a part of that glowing flame of universal love, which, after encircling humanity, mounts in a grateful incense to God. (4.53)
Wollstonecraft thinks that physical love is not the be all and end all of life, so she thinks women should learn things like philosophy and science. A more elevated kind of love—that built on mutual respect and a life of the mind—is only possible if both men and women are properly educated. It's only this elevated kind of love that can be considered truly holy.
I could not believe what my reason told me was derogatory to the character of the Supreme Being: and, having no fear of the devil before mine eyes, I venture to call this a suggestion of reason, instead of resting my weakness on the broad shoulders of the first seducer of my sex. (5.7)
Frankly, Wollstonecraft doesn't buy the idea that women are all weak because Satan seduced Eve in the Garden of Eden. She thinks instead that God created men and women to be partners in life, and therefore equal.
If it be merely the refuge of weakness or wild fanaticism, and not a governing principle of conduct, drawn from self-knowledge, and a rational opinion respecting the attributes of God, what can it be expected to produce? (5.161)
Wollstonecraft can't see any rational purpose behind the oppression of women. It just seems to be a matter of tradition simply for the sake of tradition. You can't say that men are naturally better than women without saying that God created a flawed creature when he created women, and Wollstonecraft argues that this argument is pure blasphemy.
Most prospects in life are marred by the shuffling worldly wisdom of men, who, forgetting that they cannot serve God and mammon, endeavor to blend contradictory things. (5.162)
There are lots of men in the world who want to serve God and make lots of money (the weird word "mammon" refers to material wealth). But Wollstonecraft insists that you can't have it both ways. The Bible is very clear when it comes to greed. Greed is a horrible thing and it's immoral for a person to have way more than she or he needs to live.
Probably you would not understand me, were I to attempt to shew you that it would be absolutely inconsistent with the grand purpose of life, that of rendering human creatures wise and virtuous: and that, were it sanctioned by God, it would disturb the order established in creation. (13.11)
How can people possibly argue that it is against God and nature to give women a good education? The only way you could argue this is if you claimed that God intentionally messed things up in order for humans to "fix" things by oppressing women. In short, none of it makes sense—and that's what Wollstonecraft wants us to realize.