When comparing things, 'like' is the word that links one thing/group to another.
ex. Blue --(like)-- Sea. Blue like the Sea.
'alike' is the word that comes after the things/groups are already together.
ex. Apples + Pears = (alike). Apples and Pears are alike.
'likely' = "可能性", ですから それは比較のために使用されません。
ex. It's likely going to rain.
Hope this helps! :)