Calvinism and evangelizing

If Calvinism were true, if our fates are pre determined, and if there is absolutely nothing we can do about anything because God is sovereign (which I do agree with) than what is the point of any of life?  What is the point of doing ministry, evangelizing?   That is my understanding of the doctrine, if it is a faulty one, please correct me.  This is just something that has been on my mind, lately.  I wanted to address this and what it means in terms of evangelizing, as this is a must for every Christ follower.   I have yet to come to a complete understanding of the subject of God’s sovereignty, myself, but have an idea or Biblical understanding, myself.

God is sovereign, he does not force his will or ways on his creation (man) because he respects and loves us all.  God gives us free will.  (Prov 16:9, Rev 3:20, Prov 16:1, Deut 11:26-28, 2 Peter 3:9)