Question

Why did Spain renew its efforts to establish missions and settle Texas in the late 1600s?

Answer 1

It was due to their rivalry with France.  Texas is located between Mexico which was a Spanish Colony and Louisiana which was colonized by the French.  Texas was not yet colonized at the time but Spain and Mexico realized that the area would be contested until a permanent settlement was set up.  The French tried but failed but the Spanish moved to protect their claim to Texas.