After experiencing disappointment, what important mission does God give Adventists?

Thank god!

There is no Adventist. The so-called Adventists are a group of people who focus on the exact date of Christ's return, but the Bible clearly says: No one knows that day and time. When people focus on the date of Christ's second coming, they use people's "wisdom" to guess when the Lord Jesus will come again, which brings people opportunism and self-righteousness, just the opposite of the truth in the Bible.

God's mission to his children is to go to the whole world and preach the gospel to all people. Baptize the Father and the Son in the name of the Holy Spirit, and the Lord Jesus will be with us forever until the end of the world. This is the mission of every Christian, whether it is a Seventh Day believer or other believers.

God bless you. Amen!