v. 2 "...my goodness extendeth not to Thee" KJV
God owes us nothing of any good things we do, nor God's goodness for us is conditioned upon something deserved. ~ John Calvin.
Additionally, Calvin adds, that we are in the active:
"...But I think the sentence has a more extensive meaning, namely, that let men strive ever so much to lay themselves out for God, yet they can bring no advantage to him." ~ John Calvin.
In conclusion, Calvin summed up:
"...When we imagine that there is any good thing in us, we need not wonder if he reject us, as we thus take away from him a principal part of the honor which is his due. But, on the contrary, if we acknowledge that all the services which we can yield him are in themselves things of nought, and undeserving of any recompense, this humility is as a perfume of a sweet odour, which will procure for them acceptance with God."
v. 3: The saints are my joy and example, they are not my jealousy nor standard I seek to defeat and claim my merit for my goodness is an undeserved one. It is therefore meaningless to seek merit in being better than the saints, though it is not meaningless to strive so much of it for God.
v. 4: Exodus 23:13