And Be Thankful
It's right that we want to please God because of what he has done for us. It's gratitude and one of the marks of the world's degeneracy in Romans 1 was that it lacked gratitude (1:21). So thankfulness as a response to his holy grace is to be expected in and from us.
But there's more to being thankful than being "thankful". The grateful response rises out of the awareness that something wonderful has been given to us, has happened in and to us. To eat food with thankfulness (1 Timothy 4:3, for example) involves enjoying it, receiving it with pleasure. To be thankful means more than to say "thank you" and it's more than feeling that as a responsibility however true that is. It is to receive with joy and to appreciate the loveliness and the richness of the gift. It is to respond first and foremost to the Giver but it involves a heart response that has recognised the beauty and richness of the gift.
We ask for a fish and he gives us a serpent? We ask for a loaf and he gives us a rock and we say "thank you"? We're in danger of drowning and he helps us by throwing us an anchor and we thank him? One of the joys of the Lord is that our joy is made full in his joy (John 15:11). God isn't slow to put us to grief if that serves his holy purpose but he doesn't purpose to grieve us forever. Blessing and life are his ultimate aim. So if he puts us to grief we continue to trust him and when he blesses us richly (as he does) with life and fellowship we are to enjoy it, we are to be thankful. This is a fit response to grace! If he gives you a lovely meal, eat it with pleasure and if he leads you to hunger live and learn. If he gives you salvation--rejoice in it and think it delicious. So, rejoice in the Lord and again I say rejoice.