I don't pretend to understand how God's sovereignty and omniscience work with man's free will, but I do know that both are completely true pieces to the puzzle.
Forget about Calvinism versus Arminianism for a moment, and think about the fact that God chose you. He called you. Do you feel that tug in your heart when you sin? That's the Holy Spirit warring against your flesh.
If you have accepted Christ and believe in Him, you are saved. You continue to sin, we all continue to sin, but you are saved. Who are we to question God's election?
Take a moment to ponder the mind-blowing fact that God chose you. He knew you before you were born. He chose to call you to Him.
Thank you God, for choosing me. I know I cannot live a perfect life without sin, but I also know that Christ is my advocate in Heaven, that You have called me, and that I am saved. Thank you Lord.