Baptism

“The ministers, therefore, on their part administer the sacrament and that which is visible, but our Lord gives that which is signified by the sacrament, namely, the gifts and invisible grace; washing, cleansing, and purging our souls of all filth and unrighteousness; renewing our hearts and filling them with all comfort; giving unto us a true assurance of His fatherly goodness; putting on us the new man, and putting off the old man with all his deeds. For this reason we believe that anyone who aspires to reach eternal life ought to be baptized only once without ever repeating it– for we can-not be born twice. Yet this baptism is profitable not only when the water is on us and when we receive it but throughout our entire lives.”— 

Belgic Confession, article 34 Baptism