John 20:24
ESV - 24 Now Thomas, one of the Twelve, called the Twin, was not with them when Jesus came.
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The Universal Syriac Orthodox Church under the Holy See of Antioch believes that the name of the twin brother of Thomas is Aday or Adday. My parish-church is known as Nalunnakal St Adday's Syriac Jacobite Church, Kottayam Kerala, India.. There are a number of believers in Kerala India having the name Adday; prominent among them is Rev Dr..Aday Jacob Corepiscopos, Principal of Malankara Syrian Orthodox Theological Seminary Mulanthuruthy, Ernakulam, Kerala India.