1: ἑαυτοῦ
(Strong's #1438 — Pronoun — heauton — heh-ow-too' )

is sometimes used as a reflexive pronoun of the 1st person plural, signifying "our own selves," translated "our own" in 1—Thessalonians 2:8 , lit., "(the souls) of ourselves."

2: ἴδιος
(Strong's #2398 — Adjective — idios — id'-ee-os )

"one's own," signifies "our own" in Acts 3:12; 1—Corinthians 4:12; in Acts 2:8 , with hemon, forming a strong possessive, lit., "each in his own language of us."