The congregation was organized in July 1841, but Easter 1842 shook the congregation. At this time, many of those who were against the organization of the congregation or were weak in their faith left the church. Problems concerning the doctrines to be taught and confessed in the congregation arose as well. A debate arose between whether the church should be Lutheran or a Lutheran-Reformed mixture much like the Prussian Union. Under the leadership of Rev. Schieferdecker, the Lutheran doctrines and confessions were adopted.
By Easter 1842, those who were against Lutheranism withdrew their membership from the congregation. Some of these met in the home of Phillip Baum, two miles west of Wartburg. Konrad Ries, a circuit rider based in Millstadt, led these services. May 11, 1845 brought Salem Evangelical Church, the first Evangelical church in Monroe County, into existence by Konrad and Jacob Ries. The church building was built near the Baum home, but the church closed its doors on Christmas Day, 1938. There was no resident pastor for that church during its existence.
Schieferdecker wrote that although the remaining members were few in number, the Lord Jesus Christ had not allowed his work to be completely destroyed. The church also grew stronger in their faith and unity under the Holy Scriptures.
Although the church only numbered nine families, the first church building was constructed in 1844. The land, located about two miles north of the present site, was donated by Jacob Horn. The congregation bared the major portion of the burden for this construction although the brothers in St. Louis did collect an offering of $50 to help offset the costs. This church building was dedicated on the Twenty-Third Sunday after Trinity (November 10), 1844. Rev. C.F.W. Walther, pastor at Trinity-St. Louis, who later became the first president of the Lutheran Church-Missouri Synod, officiated at the dedication.
Holy Cross was the second congregation in the county to have a church building. The Methodist church in Waterloo was the first.
In 1845 a parsonage was constructed. The community and congregation was strengthened by several new immigrant families from Prussia.
The second disaster happened between seven and eight in the evening on December 4, 1846. The chapel burned to the ground due to apparent carelessness. Services continued in the Just home until the second church building was built in August 1848.
The second building was constructed on land donated by Johann Christian and Katherine Just from their original land grant of 1839. This site was more centralized for the membership, allowing for higher attendance at services.
Dedication of the second church was on the Tenth Sunday after Trinity (August 27), 1848. Officiating at the dedication service were Rev. Rudolph Lange of St. Charles, Missouri and Rev. C. Strasen from Horse Prairie, Illinois (now called Trinity, Red Bud). Rev. Strasen was a grandfather of Rev. B.T. Strasen, the fourteenth pastor of Holy Cross.
In November 1848, a new parsonage and schoolhouse were erected at the new site.
From the beginning of his pastorate the pastor was the sole teacher of the one-room schoolhouse until a full-time teacher was called in 1856. Holy Cross Christian Day School opened ten years before the Illinois public schools, which opened in 1855.
Rev. Schieferdecker was a pioneer pastor who traveled and established St. Paul, Columbia and Holy Cross, Sugarloaf (East Carondelet) in 1841.
In 1849 Trinity, Millstadt called Schieferdecker. He accepted the call and was installed as their pastor on Ascension Day. His last official service at Wartburg was on Rogate (May 13), 1849. During his pastorate, Rev. Schieferdecker performed 53 baptisms, 23 burials and 10 marriages.
At Trinity, Millstadt, Schieferdecker had to deal with Pastor John Jacob Ries of the Evangelical congregation again. Schieferdecker had conducted bi-weekly worship services at Millstadt from 1848 until his installation at the home of Philipp Buecher. Ries led opposition for the building of Trinity's church building, but the church building was completed in 1849.
The first known Holy Cross constitution was written in March 1849. This document shows great concern for doctrinal purity as taught in Holy Scriptures and the Lutheran Confessions.
1849 and 1850 saw marked increases in membership. Twenty new voting members signed the constitution during this time frame.
The second pastor, Rev. Carl Heinrich Gottlieb Schliepsiek, signed the Holy Cross constitution and installed on Exaudi (May 20), 1849 by Rev. Schieferdecker.
The third disaster saw twenty-four members of the congregation join their Lord and Savior in Heaven due to the cholera epidemic of 1849. The youngest fatality of the epidemic was the eleven-month old son of Rev. Schliepsiek.
Those who died from cholera and listed in the church records are:
In the summer of 1849, 161 people died of cholera in Monroe County. 4000 people lost their lives in St. Louis alone between April 30 and August 6.
Schieferdecker received an urgent call from Rev. Buenger of Trinity, St. Louis to assist with pastoral care in St. Louis. At that time, cholera had not broken out in Illinois so the Millstadt congregation allowed him to serve the St. Louis people.
After only working in St. Louis for eight days, Schieferdecker received news that the disease had broken out in Illinois and in his congregation. This forced him to return to his own congregation.
Schieferdecker's family was not spared in the epidemic. Two of his children contracted cholera, one lived, the other died. His wife got it as well. She was healed by God just at the point of certain death from the disease.
The newly formed congregation in Millstadt lost nine members. Overall, the town of Millstadt lost fifty.
Cholera made another appearance in July 1866. This second attack prompted several prayer services at Holy Cross to ask God's grace and protection. The prayers were answered and no deaths were recorded from cholera from this time.
In the first ten years of the congregation's history, there are seventy deaths recorded. The earliest membership figure, dating from 1851, is fifty-seven members. It is not certain how many children were in the congregation.
Rev. Schliepsieck left Holy Cross in 1850 after eighteen months of service. He accepted a call to St. John's Church in Collinsville.