Circumcision of the flesh has no bearing on a man's salvation (Galatians 5:6, Galatians 6:15, 1 Corinthians 7:19). In fact, it can be detrimental to one's salvation if one is putting their trust in it (Galatians 5:1-4, Philippians 3:1-9).
What you mean by cherry-picking, is that you don't like it when people quote specific verses to you in order to prove their point.
I can say that you cherry-picked the verses that you quoted in the post above. Where does it end?
No one would ever be able to quote verses to prove their point. A person would just have to say, "I am right, here. Read your Bible; for the whole of the Bible substantiates what I am saying." and never, ever quote a scripture.
But when we quote specific verses, we give the reference so that you can look them up in their context.
It is also a solid rule of hermeneutics that the plain meaning of any singular verse will never be nullified by its surrounding context. Because the scripture does not contradict itself.
Thus, cherry-picking, as you call it, is not a thing to be disparaged; but it is a thing to be encouraged.
Furthermore, in Matthew 2:15, Matthew, under the inspiration of the Holy Ghost, cherry-picked out of Hosea 11:1 and even took it out of its original context and, where in the original context, the son being spoken of is Israel, when Matthew quotes it, it is referring to Jesus as the Son of God (because that is a major doctrine of the New Testament, cf. 1 John 4:15, 1 John 5:5). The Holy Spirit is able to even quote verses outside of their original context to make a point.