(Original post by Kosmos)
1) Say that you either are God or you received the word of God, now just say that it was only you that received it.
To bolster your credibility say that you were the fulfillment of an ancient prophecy, preferably one of the major religions and twist their scripture to justify you being the prophet or 'Son'.
2) Be as sincere as possible and try to recruit followers who are either illiterate or don't bother to challenge your divine experience, you could also convince your family but make sure they don't undermine your authority, if they do just say that they don't understand your word.
3) Use common magic tricks to fool your followers into believing you have mustered miracles, if this doesn't work refer to miracles that you have done in the past and make up fake witnesses so that no-one can challenge you. If neither works you can consult with your followers and make up miracles that you have done.
4) Demonize anyone who attempts to challenge you, this is easily done, just say that demonic forces (the criticizers) are trying to deceive followers into believing that you're not God or a prophet. Probably better is to say that if they do follow you they'll go to heaven for eternity and if they don't they'll go to eternal hellfire in agony, this should prevent any followers from leaving. If anyone challenges you, refer to the oral tradition which has been put onto scripture and repeat this over and over to prevent you from succumbing to the demonic forces.
5) Don't write anything down this will be used against you, instead transfer your words orally and make sure that your followers will be able to memorize the words, if you do write anything down make sure they're highly ambiguous so that future followers can use them to infer that you knew about future scientific discoveries or historical events.
6) Cut off any possibility of instigating that there'll be a future prophecy, make it clear that you are the last messenger, this will prevent anyone from changing your religion or your claims. Say that this is the last time god will intervene until the end times where you'll judge them and if anyone tries to change it they'll go to eternal hellfire.
7) If you're going to use your new-found prophet status to your advantage (i.e. having more than one wife) make sure that you justify it and allow others to do it or just say that because your God/Prophet only you will have these benefits and if you don't like it, say hello to Mr.Hellfire for me.
8) If you're going to make people follow you and give them hope that you're the right one to follow, present yourself as following the words you preach, this will not only give them confidence that your the prophet/God but will not make you out to be a hypocrite. When their backs have turned, just do whatever you like but if anyone finds out, they were under the influence of demonic forces.
9) Appeal to the majority of the population, you can do this by imagining their situation and then giving them the answers they want, for example, make out that being poor is good and that the social upper hierarchy are wrong and demonic. You have to follow this in order to make them think that you're the truth.
10) If you're for financial gain don't make it known to the followers or they might not believe you, instead create an organization which filters the finances to the followers, this will reinforce your message of the majority and prevent anyone from saying you're only doing it for finances, this will help your image. You can quite easily create a separate account and spend it in your personal leisure.
Follow these 10 commandments and you'll have yourself a religion that is not only believable but enforces you as the great one.