As it turns out, Adam needs less persuading to eat the forbidden fruit than Eve. At least when Satan, disguised as a serpent, persuaded Eve to defy God he used rational arguments, whereas Eve shamelessly plays on Adam's love for her to get him to share her fate. Eve reminds Adam that she sprung from his rib; she thus enjoys an extra special bond with him:

Adam, from whose deare side I boast me sprung
And gladly of our Union heare thee speak
One Heart, one Soul in both;
(9.965–967)

Eve is insistent that their love is so strong that nothing can separate them, not even death. That being so, Adam must share with Eve in the crime that she has committed, as well as her guilt. This will be the ultimate test of their love:

Rather then Death or aught then Death more dread
Shall separate us, linkt in Love so deare
To undergoe with mee one Guilt, one Crime
If any be, of tasting this fair Fruit
Whose vertue, for of good still good proceeds
Direct, or by occasion hath presented
This happie trial of thy Love, which else
So eminently never had bin known.
(9.969–76)

In her eloquent plea to Adam, Eve is positively evangelistic about the beneficial effects of eating the forbidden fruit. Instead of bringing them death, it will bring them "Life augmented." The taste of the fruit is so divine that it makes everything else seem flat by comparison.

Yes, Eve is perfectly aware that she's sinned against God, but she no longer seems to care. All that matters to her right now is that, whatever happens from now on, Adam will be firmly by her side. So she passionately enjoins Adam to follow her example and taste the forbidden fruit. In doing so, he will be overcoming his fear of death:

On my experience, Adam, freely taste,

And fear of Death deliver to the Windes. (9.987–988)