Wherefore the rather, brethren, give diligence to make your calling and election sure: for if ye do these things, ye shall never fall: For so an entrance shall be ministered unto you abundantly into the everlasting kingdom of our Lord and Saviour Jesus Christ. (2 Peter 1:10-11 KJV)
This is not talking about working for your salvation, but rather having assurance of your salvation. These verses point back to the Christian virtues that should be present in every believer's life. They areas follows:
If God has saved you, you will to varying degrees have these virtues in your life and will desire to cultivate them more and more as you grow in your faith in Christ. It takes effort on our part to cultivate these things in our lives, but the desire and perseverance God puts in your heart to do these things is what give you as a Christian assurance of God's calling and election.