WK lists these both as “think”, but I think it would be better if 思 was listed as something else, like “belief”, as the primary definition, or at least as a synonym. The two kanji mean different things, and having them both have the same English meaning just creates a larger chance for confusion and leeches. For two of the three example sentences for 思う, you can easily swap out “believe” for “think”.
So, “I think he’s coming, too.” would be, “I believe he’s coming, too.” I think this would be more accurate, and also reduce the chance of leeches.
Most of the English definitions of “think” line up more with 考, so that’s my main reason for thinking 思 should have a slightly different meaning, or other synonyms listed. Also, I see a couple older threads similar to this, and they both point out that 思う is more emotional, hence the 心 radical. I think this just further supports that “belief” would be a more accurate meaning for 思.
(Also, all the times I’ve used “I think” in this post could also easily be replaced by “I believe”. Haha.)