A father of one's mother is the oldest person in my family!
He became 87 this year!
He always gives me a present, and we also send messages sometimes!
And I’m the youngest!
He is the oldest and I’m the youngest, but we are good friends for each other!

“Keep on asking, and it will be given you.”​ — Luke 11:9

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A father of one's mother is the oldest person in my family!
He became 87 this year!
He always gives me a present, and we also send messages sometimes!
And I’m the youngest!
He is the oldest, and I’m the youngest, but we are good friends with each other!
= The comma before and is optional but recommended because it joins two independent clauses. 
= This is great!