Sforno on Exodus 34:14/ספורנו על שמות ל״ד:י״ד

1כי לא תשתחוה לאל אחר, this is why you must destroy altars intended for worship of such alien deities and not display any indulgence to people practicing such a religion. By indulging such people [in the name of ‘freedom of religion’ Ed.] you would be honouring such deities indirectly and you would provoke My wrath for

2כי ה' קנא שמו, G’d’s very name suggests that He cannot tolerate any other existence in the universe that purports to be independent of Him, in competition with Him. This is why He is known (in the Ten Commandments) as “a jealous G’d.” This means that He will punish those who serve the “competition.”