If God is referring to Spiritual Tithes & Offerings which the Lord Jesus obeyed (Matthew 5:17)
Nothing in Matthew's gospel suggests that Jesus obeyed "Spiritual Tithes & Offerings". That's a complete fabrication on your part.
Question: Why people today who read and believe the holy bible don't know the meaning of Spiritual Tithes & Offerings?
Answer: It is because only to the Chosen of God explained the meaning of it. But for the Unchosen it remains as Parable. And they follow it in letter or literal way only.
Hogwash. The reason people don't "know the meaning" is that
there is no such thing as "spiritual tithes". The idea simply doesn't appear in Scripture anywhere. Your answer is despicably self-righteous--that you consider yourself "chosen" and other Christians "unchosen" is the height of arrogance, and you are
very wrong.
34 But without a parable spake he not unto them: and when they were alone, he expounded all things to his disciples.
You have misinterpreted this and grossly misapplied it. Firstly, this is a context-specific statement pertinent only to Jesus' public ministry while on Earth. Secondly, it says nothing at all about the rest of Scripture. Thirdly, it says nothing about people reading, interpreting, and applying Scripture.
Scripture is confusing in places, as Peter notes, and we need the Holy Spirit to help us understand it fully, but that doesn't mean it is completely incomprehensible, and definitely not that only certain people are "chosen" to understand it. Your stubborn insistence that everything has an opaque "spiritual" application is leading you far astray. Get some sound Bible teaching and stop misinterpreting it so badly, lest you waylay yourself into heresy.