It should be an evident witness to us that there is a real and good God. All that God has given us, His creation to provide for us, His commandments to help us in life, and the power of the Holy Spirit proves that God is our good creator and God. But those who reject what God has given us, His provision, commandments, and His spiritual gifts, do not believe in who God is and also reject God. Deuteronomy 8:2 NKJV says, "The LORD your God led you all the way these forty years in the wilderness, to humble you and test you, to know what was in your heart, whether you would keep His commandments or not." Just like God gave Israel His provision in the desert to all those there, God gives us these blessings, His provision in this Messianic time. God tests us to see if we will believe in who He is and all He has given us.
Those that do not pass the test will insult the spirit of grace and be judged for their lack of belief in the creator God who gave us good commandments and the gift of the Holy Spirit. Also, we should note that God will judge those who misuse the gift of the Holy Spirit. 1 Corinthians 14:40 NKJV says, "Let all things be done decently and in order." It is a commandment of God the Bible says.
Hebrews 10:29-30 NKJV says,
How much worse punishment, do you suppose, will he be thought worthy who has trampled the Son of God underfoot, counted the blood of the covenant by which he was sanctified a common thing, and insulted the Spirit of grace? For we know Him who said, "Vengeance is Mine, I will repay," says the Lord.
Also, Hebrews 12:14-15 NKJV says, "Pursue peace with all people, and holiness, without which no one will see the Lord: looking carefully lest anyone fall short of the grace of God." Be careful to not fall short of God's grace. Holiness is to keep God's commandments. Deuteronomy 28:9 NKJV says, "The LORD will establish you as a holy people to Himself, just as He has sworn to you, if you keep the commandments of the LORD your God and walk in His ways." God will make you a holy person, if, you keep God's Old Testament commandments. God's true holy people follow God and that includes believing in Yeshua Messiah in this Messianic era. Matthew 5:17 NKJV says, "Do not think that I came to destroy the Law." So, those who say the Old Testament law is done away with also do not believe in the Messiah Yeshua. Yeshua said that while the earth exists, the law will exist until everything that is supposed to happen will happen. Matthew 5:18 NKJV says, "Till heaven and earth pass away, one jot or one tittle will by no means pass from the law till all is fulfilled." Not all has been fulfilled yet. There is still a new heaven and earth to come. Revelation 21:1 NKJV says, "Now I saw a new heaven and a new earth, for the first heaven and the first earth had passed away."