The following information is quoted directly from www.lcms.org/faqs/denominations.
What are the major differences between Lutheran churches and Reformed (or Calvinist) churches?
Just as there are many significant differences in theology and practice between Lutherans of varying denominations, the same is true when it comes to different churches within the Reformed tradition. Differences exist among Reformed churches even regarding such fundamental issues as the authority of Scripture and the nature and centrality of the doctrine of justification.
Historically, however, most Reformed churches adhere to the five points of Calvinist theology commonly summarized by the acrostic “TULIP” as these were set forth at the Synod of Dort (1618-1619). On page 41 in his book, Churches in America, Dr. Thomas Manteufel reviews these five points and explains how they compare and/or contrast with what Lutherans believe regarding these matters.
T (Total Depravity)
The Calvinists rightly teach that all descendants of Adam are by nature totally corrupt in spiritual matters. People do not have freedom of the will to turn to God in faith or cooperate in their conversions (Eph. 2:1; John 3:5-6; Rom. 8:7).
U (Unconditional Predestination)
Scripture does teach that it is by grace that God has predestinated the elect to eternal salvation and given them justifying faith. It is not because of any condition fulfilled by them (2 Tim. 1:9; Eph. 1:4-6; Phil. 1:29). However, the Bible does not teach, as do the Calvinists, that some are predestined for damnation. God wants all to be saved (1 Tim. 2:4).
L (Limited Atonement)
It is true that Christ died for the church and purchased it with His blood (Eph. 5:25; Acts 20:28). Furthermore, His atoning death does not mean that all people are saved (1 Cor. 1:18). However, Jesus died for all (2 Cor. 5:15).
I (Irresistible Grace)
We agree that God makes us alive by His mighty power, without our aid (Eph. 2:5; John 1:13). But Scripture warns we can resist God’s gracious call (Matt. 23:37; Acts 7:51; 2 Cor. 6:1). And some people do resist God’s grace, or all would be saved (1 Tim. 2:4). Furthermore, God warns us not to resist His grace (2 Cor. 6:1; Heb. 4:7).
P (Perseverance in Grace)
We affirm with Scripture that those who are predestined to salvation cannot be lost but will continue by God’s power to a blessed end (Rom. 8:30; 1 Peter 1:5). Scripture does not teach, however, that those who come to faith cannot lose that faith (Heb. 6:4-6; 10:26-29; Ps. 51:11). God urges His people not to continue in sin but to live in repentance and faith (Rom. 6:1-4).