Here is a rapper of their theology.
Below is from the Heidelbery Catechism.
74. Q. Should infants, too, be baptized?
A. Yes. Infants as well as adults belong to God's covenant and congregation. Through Christ's blood the redemption from sin and the Holy Spirit, who works faith, are promised to them no less than to adults. Therefore, by baptism, as sign of the covenant, they must be grafted into the Christian church and distinguished from the children of unbelievers. This was done in the old covenant by circumcision, in place of which baptism was instituted in the new covenant.
btw, the calvinist are some of the biggest 'men worshipper' around, note that when Kevin D and C.J. are mention the crowd cheers.