We suffer because of Adam and Eve disobey God. God send his only son to save us from our sins. But if you commit a sin you already disobey God so that where the suffering comes from. And there are many Bible verse that talks about our Tribulation here on earth. In my own opinion, if you are suffering now, you must pray to God, repent your sins and don't do it anymore. About the diseases, wars, conflicts etc., these events is Satan's plan to deceive us and put away our faith on God. You said that you beleive in God. Always remember. It doesn't mean that if you believe in God, you are saved. Satan also believes in God but he disobey him. If you believe in God but you are not doing his will, then you are not saved when Jesus returns.