Jesus said in Matthew 26:18-20, "go and make disciples of all nations, baptizing them in the name of the Father and of the Son and of the Holy Spirit, and teaching them to obey everything I have commanded you. And surely I am with you always, to the very end of the age."
Question: If a believer fails to get baptized, do the ones who "made a disciple" of that person fail God in the sense of consequence that separates them from God for eternity? What of the one who is not baptized? What if there is a really, really GOOD reason for his not being baptized? (I've known of a few people who were terminally ill with cancer in the hospital who were saved in their last days and weeks but who were not baptized in water.)
Yet, Jesus said "baptize them". In the same statement ..... in much closer proximity to anything He ever said about tithes, He said, "teaching them to obey everything I have commanded you" (which, IMO, would include right instruction on faithful giving).
I doubt any of us would read Jesus' statement that is EMPHATIC as being a baptismal test of salvation. Maybe some of us would. What I haven't seen, though, is anyone here who would, in spite of their most passionate and well-considered views on tithing, call it a "test of salvation". So, when we speak of a "requirement", be it baptism or tithing, let us not be drawn into a false "heaven or hell" dichotomy about the consequences of failing in that requirement. In some, maybe many, instances, the dilemma could be what you might call "eternally determinative" like that; but, that would mean (IMO) questioning one's ever having been a believer, which seems far more likely to me to be the real issue here.
In other, shorter words, I need to ask myself and you need to ask yourself and the church needs to humbly stand on the authority given to it by God Almighty and ask --- "Am I a follower of Jesus or am I not?" If I answer "yes", I need to be prepared and preparing to pay the price for that decision, and there is a price. It is my whole life.
(Oh, my, I just learned something about myself.....not good.)

Seriously. If I tithe, or if I am baptized, or if I am faithful in so many deeds and works, but if I am withholding my service in someway (and, we're capable of really contorting ourselves around justifications and what look like good reasons for doing or not doing things), have I not then violated the most elementary aspect of His commands?? The questions go so much deeper within us than simply tithing or not. I would confess that I have not always been faithful on tithing. But, as that was the case, I was also more not faithful in other matters.
I can see in my life a clearer relationship between financial faithfulness to God and a starkly improved view of my other shortcomings so that I might know whereof I NEED to repent and grow and change and transform and obey. This takes time, or it does/has for me.
Human government bears the same relation to hell as the church bears to heaven. (David Lipscomb, On Civil Government, 72).