The Early Christians would sooner die than lie, and their confidence was contagious (Acts 4-5). Luke was an Early Christian. Luke was a man of integrity.
Luke was “the beloved physician” (Col. 4:14), a master of the Greek language, and a careful historian. Luke was a man of ability.
The question of questions can be answered by a simple question. “Is the Christian religion the true religion?” is the question of questions. “Is Luke trustworthy?” is the simple question.
In his Preface (Lk. 1:1-4, cf. Acts 1:1) Luke assures us that his account is accurate. If it is – and it is – that means that Jesus fulfilled the Old Testament, was born of a virgin, made the lame to leap for joy, and rose from the dead. That means Jesus is the Christ and Christianity is true.