Our God is good, Always. It's one of the main attributes of the God of the bible. You can trust Him to be Good in all His dealings.

Psalm 84:10 For a day in your courts is better than a thousand elsewhere. I would rather be a doorkeeper in the house of my God than dwell in the tents of wickedness. 11 For the Lord God is a sun and shield; the Lord bestows favor and honor. No good thing does he withhold from those who walk uprightly.

God has great plans for us and we can have it all once we submit to be guided by Him. God wants to give all good things to those who love Him. David realised this and noticed that once he repented of his errors God forgave him and brought him back into a good relationship with Him.

We also are in a similar, yet better situation regarding our walk with God. Once we live with a repentant attitude, submitted to God and guided by Holy Spirit, He gives all good things to us when we ask. In fact even before we ask He answers us!

And, He has provided the means through His Son Jesus Christ for us to live uprightly before Him.

Romans 4:5 But to him that works not, but believes on him that justifies the ungodly, his faith is counted for righteousness. 6 even as David also describes the blessedness of the man, to whom God imputes righteousness without works, 7 saying, "Blessed are they whose iniquities are forgiven, and whose sins are covered. 8 Blessed is the man to whom the Lord will not impute sin".

To say that God will punish them and give Christians diseases because of their sins is to say that He is a liar and His word cannot be trusted. He IS imputing our sins against us.

The truth though is that our God has made us righteous in His Son. Our response to such a Good God is to love Him and live for Him. And while Satan will come against us, we know that we will win, and as we walk with God we know also that, "No good thing will he withhold from us".