It is possible to be a Christian, a Jew, a Muslim, A Buddhist or A Hindu and have an intelligent, discursive and compassionate theological approach you know MT.
the phrase 'spare the rod spoil the child' is not a biblical quotation. It comes from a Samule Butler poem from the 17 th century. there is a phrase in Proverbs "He that spareth his rod hateth his son: but he that loveth him chasteneth him betimes (diligently)." There are various ways of interpreting this sentence. Firstly, Proverbs were assembled by King Solomon, [circa 1000BCE] Basically he was assembling a set of sayings and quotes that went back centuries before him - so they were cultural, not religious in origin, and certainly not Christian.
Secondly, one has to remember that the King James version of the Bible is a bit like Chinese Whispers - the layers of interpretation get in the way and obliterate poetry, metaphor and subtle nuances.
Thirdly, if one takes the saying as a metaphor, and God is the parent and the we are the child, then the phrase becomes rather similar to the Buddhist central conceit - that Life is Suffering. It does not me you should beat children, rather that suffering is an inevitable part of life which makes up grow.
I find both some athiests and the most frightening sorts of Evangelical Christians fall into the same trap of taking the Bible literally and having no ability to have intelligent theological discussion.