If you love those who love you, what thanks do you have? If you do good to those who do good to you, what thanks do you have? For sinners do the same. Rather, love your enemies and do good, and lend, hoping for nothing; then your reward will be great, and you will be sons of the Highest. Luke 6:32-35.

That no good deed performed by a person, if it is to be truly good, commences in himself, only in the Lord, is likewise the Lord's teaching, in John,

Man cannot receive anything unless it is given him from heaven. John 3:27.

And elsewhere,

Jesus said, I am the vine, you are the branches. He who abides in Me, and I in him, he it is that bears much fruit, for without Me you can do nothing. John 15:5.