If I am not mistaken, in order for a person to be confirmed, they must answer “yes” to this, among other, questions, “Do you believe everything the Catholic Church proposes in matters of faith and morals?” or something to that effect.
Thus if a person did not believe, would they not be lying?
Lying when taking a marriage vow invalidates the sacrament of marriage. Lying during the sacrament of confession invalidates the confession and absolution. Why wouldn’t lying during confirmation invalidate it?
I’m not sure about such a blanket statement vis the marriage but:
In all sacraments, as you know, the scholastics speak of the “matter” and “form”, matter being divided into proximate matter and remote matter.
With regard to penance, sins are the “remote matter”. Some theologians, following the opinion of St. Thomas held that the confession itself was part of the proximate matter. If one goes with that theory, then the sacrament is obviously invalid since the matter is lacking.
When one examines the sacrament from a juridical viewpoint, it becomes simpler. A judge passes a verdict based on the accusation. If something was wrong about the accusation, then the verdict has to be re-evaluated. Or if you take it from a medicinal viewpoint: the doctor’s diagnosis is dependent on the patient’s medical information. Likewise, the absolution of the priest is dependent upon a sincere confession of all sins.
With regard to marriage, in the Latin Church, the couple are the ministers and the ‘matrimonial contract’ * provides the matter and the form- that being expressed through consent as in the vows. A contract is made with certain assurances- in the case of matrimony, the duties of the Christian marriage. It thus follows that certain types of falsehoods break the assurances of the contract. Equally, in the minister of the sacrament, the correct intention is required. In the Latin Church, the couple are the ministers- thus lying (in certain cases) can also involve a defect in intention.
None of this applies to Confirmation. In Confirmation, the minister is the bishop, or priest delegated. The remote matter is the chrism, the proximate matter the application to the forehead with the hand. Hence the sacrament can be validly conferred (as long as there are no other impediments like the person is not-baptised or is dead). That does not mean that the grace is automatically received since the recipient can hinder it by mortal sins.
The reception of sacrament is invalid if the recipient is an adult but does not intend to receive the Sacrament. But this is different from disbelief, lack of faith, lack of belief in the effects of the Sacrament, etc. The intention to receive a sacrament is not the intention to profess the faith of the Church. Thus lying to a question like “Do you believe in the communion of saints?” has no impact on validity but lying to a question like “Is it your wish to be confirmed?” does.
For example, one can say mentally “OK fine, I’ll receive what this dumb Church is conferring on me” and he will receive the sacramental ‘seal’ of Confirmation but NOT the grace because of disbelief.
*I suppose I should more accurately say covenant which all valid Christian marriage contracts are