Is this enough stuff for a weeklong spiritual journey into the desert?

You'll need a whole crap load of water and possibly more than a gram of herb(assuming herb is weed). For a week I'd take at least a half ounce. I have no experience with mescaline,peyote,cubensis or brigesii.

I'm sure you know better than I what kind of camping gear you'll need for the desert,but don't forget toilet paper(rookie mistake)

I'd suggest you leave behind at least one person that knows where you went and when you'll be back and what you'll be doing.

Ask someone experienced with the desert. Lots and lots of water would be good, along with mobile phones, food (preferably stuff you won't have to cook and that will be preserved easily), matches, a map, a compass or gps, blankets etc (remember it will get cold at night), a good first aid kit, stuff like that. Remember to tell someone where you're going (although not necessarily why) and ask them to call you or get help if you're gone for more than a week or two.

Remember you'll always underestimate how much water you need, especially in the desert.

You actually have all the spiritual stuff already too... you don't need the mind altering drugs, I mean "herbs", to get in touch with that which exists within your being. All these substances do is intoxicate you to the point where you may think you've had a spiritual experience, but in reality, you're just high. The most enlightening experiences come when we are clear and present, not drugged out of our mind.

You will need more herb to take the edge off.

Water. I recommend water.

Whoops - no spiritual journey involves drugs or chemicals that change your perception or the way you feel as that blocks you from God.