This is exactly why I not only believe in, but embrace predestination. It is the crowning pinnacle of assurance to the believer-if God Himself chose us, how can we be seperated from Him? How can we extract ourselves from His grip?
The real concern about Calvinism expressed in these articles is not that it is doctrinally incorrect, but rather is that lazy, unregenerate people will use it as an excuse to shelve the great commission. This fails to take into account the work of the Holy Spirit. A believer who has become a son of the Kingdom through the blood of Christ and who has tasted the gift of the Holy Spirit will be moved to fulfill the commission by the same God who foreordained his salvation! If anyone is not, the work of sanctification has not begun in him and he must be careful to examine himself:
2 Corinthians 13:5
5 Test yourselves to see if you are in the faith; examine yourselves! Or do you not recognize this about yourselves, that Jesus Christ is in you--unless indeed you fail the test?
Or:
Hebrews 12:14
Pursue peace with all men, and the sanctification without which no one will see the Lord.
I'm not sure that people who would be daunted into abandoning the great commission by a simplistic (and invalid) logical exercise should be evangelizing and making disciples, anyway. They are not yet ready for the meat of the word (Heb. 5:12).