In a custody dispute between parents of different and conflicting religious persuasions, the trial court cannot, under the system of law that it is appointed to administer, look at the parents’ religious beliefs and choose one over the other. Waites v. Waites, 567 S.W.2d 326, 332 (Mo. banc 1978).

We reiterate our determination that the Missouri Constitution contemplates a strict and pervasive severance between religion and the state. Any suggestion that a state judicial officer were favoring or tending to favor one religious persuasion over another in a child[-]custody dispute would be intolerable to our organic law. Judges should not even give the appearance of such preference or favor.

Id. at 333. The Waites Court held that “no judicial officer may determine child custody based on approval or disapproval of the beliefs, doctrine, or tenets of the religion of either parent or their interpretation thereof.” Id. The Court explained that “[i]nquiry into religious beliefs per se is impermissible; inquiry into matters of child development as impinged upon by religious convictions is permissible ….” Id.

We agree that the trial court erred in conducting portions of its inquiry. While we caution the trial court to be mindful of the caselaw and to “not even give the appearance of such [religious] preference or favor,” we do not agree with the husband’s assertion that it affected the court’s child-custody determination. To obtain relief on appeal, a party must demonstrate not only error, but also prejudice [in the sense of a likely effect of the error on the result, not in the sense of bias as such -EV]. We shall not disturb a trial court’s judgment in a dissolution action where there is no showing of prejudice as a result of that judgment. The trial court heard substantial evidence of the children’s continuing difficulty adjusting to their new situation, particularly the significant problems encountered by the older child. The judgment reflects that the trial court considered the parenting plan submitted by each party and the guardian ad litem, and the trial court articulated a reasonable basis for adopting the wife’s plan while modifying it to give the parties joint physical custody.