i-adjective
devout; deeply religious
Describes a person who is deeply committed to their faith, often used for sincere religious devotion.
彼女は信仰深いクリスチャンです。
She is a devout Christian.
祖母は毎朝お祈りをする信仰深い人だ。
My grandmother is a devout person who prays every morning.
Compound of 信仰 (faith, belief) and 深い (deep), literally 'deep in faith'.