意思是一样的，只是“如此”更书面化，两个可以替换。同义词没必要较真他们的区别，学会如何固定搭配就好了

感觉都差不多，基本上可以互换，没必要区别。

“如此” is usually used with “原来” as a combination. EX: A: I lived in Korea for many years so I can speak Korean fluently. B: “原来如此” / No wonder. “如此” can also be used to emphasis your expressions. EX: 今天的天气如此晴朗！ / What a sunny day today! “这样” has almost the same meaning as “原来如此”. EX: A: I lived in Korea for many years so I can speak Korean fluently. B: “这样啊” / No wonder. “这样” also means "well". EX: 我今天没有空。这样吧，我们明天早上见面怎么样？ / I'm not available today. Well, how / what about tomorrow morning we meet each other? I hope that woule be helpful to you. Zhao Lei

这样 偏口语。如此 偏书面语。两者区别不大。如的意思是 像，此的意思是 这样。如此就是像这样的意思。

"如此"基本可以认为==“像这样” 而在中文中“像”又会经常因为习惯而被省略掉，所以两个词用法基本相同。打个比方“原来如此啊”你可以说成“原来（像）这样啊”。