Lutherans believe that baptism is a promise of God, not the commitment of a Christian. Therefore we also baptize infants, believing that they too have been included in the promise of God. Even as infants understand their relationship to their biological parents long before they are able to verbalize that relationship, so an infant can understand a relationship with God long before he or she can verbalize it. Faith can live in an infant or an Alzheimer's patient as easily as a fully functional adult because faith is not dependent on intellectual understanding.