How do Calvinists interpret 2 Peter 1:10? Therefore, brothers, be all the more diligent to confirm your calling and election, for if you practice these qualities you will never fall. - 2 Peter 1:10 (ESV)


This seems to suggest that we have some level of influence over whether we finally end up among the elect, and that idea is contradictory to the Calvinist teaching of Unconditional Election. So how do Calvinists interpret 2 Peter 1:10?
Calvinists from Calvin to the present day have interpreted this verse as relating to man's assurance, not God's will.  

John Calvin specifically responds to those who say this verse implies that the "stability of our calling and election depends on good works," saying:


  [P]urity of life is not improperly called the evidence and proof of election, by which the faithful may not only testify to others that they are the children of God, but also confirm themselves in this confidence, in such a manner, however, that they fix their solid foundation on something else.1


That is, good living can be correctly called proof of election, in that it is a testimony to others and to oneself of one's election, but this does not imply that good living is the foundation of election.

Jamieson, Fausset, and Brown argue that God's steadfast will needs no assurance, but man does, and good works provide it: "There is no uncertainty on His part, but on ours the only security is our faith in His promise and the fruits of the Spirit."2

Louis Berkof likewise uses this verse as evidence that "believers can in this life attain to the assurance of salvation."3 Similarly, John Frame cites this verse and says, 


  Calling is a gracious act of God, but it inevitably produces good works in the believer, works that demonstrate that one is in fact called.4





Calvin, Commentaries on the Catholic Epistles
Jamieson, et al. Commentary Critical and Explanatory on the Whole Bible
Berkhof, Systematic Theology, 4.11.C
Frame, Systematic Theology, p940