Calvinism, also known as Reformed theology, is a system of biblical interpretation that focuses on the supreme sovereignty of God, His majesty, His holiness, etc. It relates this to man's fallen, sinful nature. Because of the great chasm between God and man and because of man's sinfulness, God must predestine people into salvation...or none would be saved. Therefore, salvation is the work of God and we are the recipients of His gracious election.
I do not believe however that if someone rejects these tenets that I must reject them or that they are not Christians.
Rom. 9,15 For He says to Moses, “I will have mercy on whomever I will have mercy, and I will have compassion on whomever I will have compassion.” 16 So then it is not of him who wills, nor of him who runs, but of God who shows mercy. 17 For the Scripture says to the Pharaoh, “For this very purpose I have raised you up, that I may show My power in you, and that My name may be declared in all the earth." 18 Therefore He has mercy on whom He wills, and whom He wills He hardens.
19 You will say to me then, “Why does He still find fault? For who has resisted His will?” 20 But indeed, O man, who are you to reply against God? Will the thing formed say to him who formed it, “Why have you made me like this?” 21 Does not the potter have power over the clay, from the same lump to make one vessel for honor and another for dishonor? 22 What if God, wanting to show His wrath and to make His power known, endured with much longsuffering the vessels of wrath prepared for destruction, 23 and that He might make known the riches of His glory on the vessels of mercy, which He had prepared beforehand for glory....NKJV
Rom.8,29" For whom He foreknew, He also predestined to be conformed to the image of His Son, that He might be the firstborn among many brethren. 30 Moreover whom He predestined, these He also called; whom He called, these He also justified; and whom He justified, these He also glorified." NKJV
EPH 1,4-5 just as He chose us in Him before the foundation of the world, that we should be holy and without blame before Him in love, 5 having predestined us to adoption as sons by Jesus Christ to Himself, according to the good pleasure of His will...
And for another teaching video CLICK HERE.
If you watched the above video and you want to know more, then I recommend the following book below by: R.C. Sproul. CLICK HERE to read...
And for a deeper understanding of this subject I also recommend the following book below by: James White. CLICK HERE TO READ.