Hi Sam！
I can see you made an effort on this essay. I see you have looked up difficult words such as 緊急事態宣言 and 協会。Good job! It is good to challenge yourself to use new vocabulary.
It's interesting to read how church communities are adapting to this difficult crisis. I could understand the meaning of all the sentences and the overall text.
For the overall text, I would recommend using interpunction （、）after particles such as は、で、から、ので、to make the sentences more legible. Also, don't forget to put a full stop 。 at the end of your sentences.
教会のストリーミングについて<s style="color: rgb(230, 0, 0);">は</s>
今日は日曜日です。普通のばあい (1) は、毎週日曜日の朝<s style="color: rgb(230, 0, 0); background-color: rgb(250, 204, 204);">は</s>に (2) 教会に行きます<s style="color: rgb(230, 0, 0); background-color: rgb(250, 204, 204);">けど</s>が、 (3) 緊急事態宣言<s style="background-color: rgb(250, 204, 204); color: rgb(230, 0, 0);">から</s>が出ていますので、(4) 毎週YouTubeで教会に参加します。
<s>どこでも世界にいるんで（</s>５）<s>Youtubeの教会には</s>
世界中(せかいじゅう）の教会（churches all around the world)は、ユーチューブをしていますので、コメントやシェアーをすることが<s style="color: rgb(230, 0, 0); background-color: rgb(250, 204, 204);">できるやシャーする</s>でき<s style="color: rgb(230, 0, 0); background-color: rgb(250, 204, 204);">る</s>きます。(６)
とても便利だろう。
<s style="background-color: rgb(250, 204, 204);">けど</s>しかし、ちょっと寂しい気持ちがあ<s style="background-color: rgb(250, 204, 204);">る</s>ります － 普通<s>の</s>は、皆で集まて<s style="background-color: rgb(250, 204, 204);">しますと</s>、一緒にたべ<s style="background-color: rgb(250, 204, 204);">ます</s>るからです。
Explanations:
1) The Hiragana reading for 場合 is ばあい. In this case, you can also use this word: 普段（ふだん）.
It means 'normally' 'usually'. In this sentence, you'd say, 普段は、毎週日曜日etc... .
2) You have already used the は particle once in your sentence. You can only use は in a sentence one time! In this sentence, 'what you normally do' is the topic of the sentence, so you use は to indicate the topic after ばあい。What you normally do on a Sunday, is go to the church IN the morning. So に is appropriate in this sentence.
3) けど is appropriate in meaning but it is too colloquial. You are using です and ます forms, so が is more appropriate.
4) から means "from" when you place it after a noun. Indeed, it can mean "because", but only when you place it after a verb. In Japanese, you have to specify the situation with a verb in order to give it as a reason for something. In English you could say "because of the emergency warning, I could ... blabla.". In Japanese, you would say "Because there is a emergency warning, blablabla.". Do you see the difference?
In this sentence, I replaced から with ので because ので is more formal and thus appropiate.
5) いるんで is fine but it is only used in spoken language. いますのでis better in written text.
6) when you use や、you do not have to repeat the verbs if they are the same.
するできる correct form is することができる
