Revelation 5:9
And they sung a new song, saying, Thou art worthy to take the book, and to open the seals thereof: for thou wast slain, and hast redeemed us to God by thy blood out of every kindred, and tongue, and people, and nation;
Revelation 5:12
And every creature which is in heaven, and on the earth, and under the earth, and such as are in the sea, and all that are in them, heard I saying, Blessing, and honour, and glory, and power, be unto him that sitteth upon the throne, and unto the Lamb for ever and ever.
I can rejoice knowing that it is not of my own works or my own accord that I have been saved. That I can rest in His grace, knowing that He has overcome it all.
Receiving a free gift is not a work. If my mother decides to give me a new car, she did the work to earn the money, she bought the car with her own earnings and simply gave it to me. I could be proud and tell her I can take care of myself and reject that gift or I can free except it and be grateful. If I receive it, I still did nothing to get it or earn it.
Calvinists are the ones IMO who want to make it complicated.