Why do we thank God?
Because He is good to us!
"O give thanks unto the LORD, for he is good: for his mercy endureth for ever." (Psalm 107:1)
His grace, His goodness, is never-ending.
Thanksgiving from us is the new sacrifice that we give to God, because Jesus was the final blood sacrifice, and His blood cleanses all sin, rather than merely atoning for sin once a year:
"But this man, after he had offered one sacrifice for sins for ever, sat down on the right hand of God;" (Hebrews 10: 12)
The blood of Jesus is--present tense--better than anything spilled from an animal:
"But Christ being come an high priest of good things to come, by a greater and more perfect tabernacle, not made with hands, that is to say, not of this building; 12Neither by the blood of goats and calves, but by his own blood he entered in once into the holy place, having obtained eternal redemption for us. 13For if the blood of bulls and of goats, and the ashes of an heifer sprinkling the unclean, sanctifieth to the purifying of the flesh: 14How much more shall the blood of Christ, who through the eternal Spirit offered himself without spot to God, purge your conscience from dead works to serve the living God?" (Hebrews 9: 11-14)
His Blood is perfect!
His blood cleanses us forever!
"But if we walk in the light, as he is in the light, we have fellowship one with another, and the blood of Jesus Christ his Son cleanseth us from all sin." (1 John 1: 7)
"My little children, these things write I unto you, that ye sin not. And if any man sin, we have an advocate with the Father, Jesus Christ the righteous: 2And he is the propitiation for our sins: and not for ours only, but also for the sins of the whole world." (1 John 2: 1-2)
Jesus is in the Helping, Saving business. Let's call upon Him in our time of need:
"Let us therefore come boldly unto the throne of grace, that we may obtain mercy, and find grace to help in time of need." (Hebrews 4: 16)