The word tithe comes from the Hebrew word ma`aser {mah-as-ayr'}, which means payment of a tenth part or the Greek word apodekatoo {ap-od-ek-at-o'-o}, which mean the same thing.
I do not believe that people have a problem with the word tithe or tithing, the problem is a heart problem, which is giving up $10.00 which really does not belong to them. They use tithe or tithing as an excuse for not giving because they are selfish and does not realize that everything they have is a blessing from God.
True there are no modern days Levites as it relates to the OT type of Levites in the United States. However, the modern day ?Pastors, Preachers, Minister? are the typology of OT Levites, because of their spiritual responsibility. The Leviticus Priest was responsible for spiritual needs of Israel or they were the conduit between Israel and God. In modern day Christianity, Christ is the conduit and yes he is the High Priest. Also, comparing the responsibility of the Leviticus Priest to the modern day ?Spiritual Leader? notice one of the responsibilities of the Elders and Preachers.
?Obey them that have the rule over you, and submit yourselves: for they watch for your souls , as they that must give account, that they may do it with joy, and not with grief: for that [is] unprofitable for you?. Hebrews 13:17
This the similar responsibility that God charged the Leviticus Priest, they did this through annual sacrifices in the temple, today we are to present ourselves as a living sacrifice, holy and acceptable only to God [not the preacher] which is our service [worship]. However, God still used the minister to deliver His word just as he did the Prophets in the OT.
?How then shall they call on him in whom they have not believed? And how shall they believe in him of whom they have not heard? and how shall they hear without a preacher? ? Romans 10:14
You cannot separate the OT from the NT, well depending on how you are trying the seperate the two. They go hand and hand ? they fit together like hand and glove. Why, if any one read the scriptures, you will see that Jesus and the Apostles quoted directly from the OT. I have forgotten the % but it?s close to 30% of the NT refers back to the OT. And the OT is full of NT prophecies. I believe it was 50 Prophecies that Jesus fulfilled from the OT.
Jesus believed that the OT was divinely inspired, the infallible Word of God. He said, "The Scripture cannot be broken" (John 10:35). He referred to Scripture as "the commandment of God" Mat.15:3 and as the "Word of God" Mat. 15:6. He also said that ?beyond the shadow of doubt? it was indestructible: "Until Heaven and earth pass away, not the smallest letter or stroke shall pass away from the law, until all is accomplished" Mat. 5:18.
In fact Israel / Hebrews are called God's Church in the wilderness.