When it comes to tithing which will invoke God's wrath more?
If you are "saved", then you are in fact saved from the wrath of God.
When we are saved and in Christ, we aren't looking for which works will save us, because none of our works have that ability. Only the perfect works of Christ can save us from the wrath of God.
However, when we are saved from God's wrath, we experience His Love, which causes us to want to do things that are pleasing to God. (We love, because He first loved us).
The question should be then what makes God happy? What kind of behavior does God think is pleasing - according to Scriptures?
Since God loves a cheerful giver (2 Corinthians 9:6-7) I would put cheerful giving pretty high on the list of things that are pleasing to God.
However, sometimes it's simply habit forming to be obedient, and this has it's benefits too as your creating new pathways to bring all aspects of your life in line with His way, even if it first it seems a little begrudgingly.
There's a point to make here, everything you do is freely given to Him, whether out of a desire to bring your ways in line with His ways, or whether your cheerful at it.
It's not transactional. Your not buying heaven.