The words resonate, resinate sound the same but have different meanings and spellings. Why do resonate, resinate sound the same even though they are completely different words?
The answer is simple: resonate, resinate are homophones of the English language.
To impregnate, permeate, or flavor with resin.
To exhibit or produce resonance or resonant effects.
To evoke a feeling of shared emotion or belief: "It is a demonology [that] seems to resonate among secular and religious voters alike” ( Tamar Jacoby).
To correspond closely or harmoniously: "Symbolism matters, especially if the symbols resonate with the larger message” ( William Greider).
To cause to resound.
Definitions from The American Heritage® Dictionary of the English Language, 4th Edition and Wordnik.
Homophones (literally "same sound") are usually defined as words that share the same pronunciation, regardless of how they are spelled.
If they are spelled the same then they are also homographs (and homonyms); if they are spelled differently then they are also heterographs (literally "different writing").