When Patrick Henry addresses the Virginia Convention, he does so with at least a little trepidation, for he is about to speak words and ideas that could be considered treasonous. He begins his Speech to the Virginia Convention by suggesting, respectfully, that what is at stake here is the future of the country. He says:

I consider it as nothing less than a question of freedom or slavery; and in proportion to the magnitude of the subject ought to be the freedom of the debate.

He rather scolds the members for not wanting to hear the complete truth, so the first thing he does is encourage them to hear the whole truth and reasoning so they can make a better judgment about whether or not to take appropriate action. Then he begins to systematically build an argument for the creation of a militia.

First, he wants the members of the House to judge the future based on the past; if they do, they will see that there is no hope of change or reconciliation. Time after time, petitions have been spurned, military actions continue, and violence has been done. Nothing has changed has changed for the better.

Our petitions have been slighted; our remonstrances have produced additional violence and insult; our supplications have been disregarded; and we have been spurned, with contempt, from the foot of the throne.

Second, he wants the members of the House to consider when they will ever be in a stronger position, given that the British tentacles (he calls them chains) are creeping closer and entangling the colonists more every day. 

Third and most importantly, Henry wants the House of Burgesses to raise a militia to fight against the British rather than risk becoming more enslaved than they already are. He reminds them that God will fight with them if they act now and for this just cause.

There is a just God who presides over the destinies of nations; and who will raise up friends to fight our battles for us. The battle, sir, is not to the strong alone; it is to the vigilant, the active, the brave.

Finally, he wants the members of the House to recognize the reality that the war has already begun, and standing idle while others are fighting should not be an option for the people of Virginia. He ends his famous speech, of course, with his famous cry:

I know not what course others may take; but as for me, give me liberty or give me death!

Patrick Henry's argument works, and the House of Burgesses in Richmond, Virginia, votes to create a militia just months before war against Britain is declared.