Some disciples were not aware that they were no more under the Law (Galatians 3:24-25). Hence, they were teaching fellow disciples to still keep the Law. Meanwhile, they needed to be taught that the Law has been taken away from the way of salvation (cf. Colossians 2:14-17; 2 Corinthians 3:14; Hebrews 8:6-13).
They eventually learnt that it is must to leave Judaism because the Old Testament has completed his work.
In Acts chapter 15, it was a serious debatable subject among the disciples as to whether they need to keep the Law of Moses as well as to be circumcised (cf. vs. 1-5).
The matter was thoroughly discussed and they learnt that keeping the Law was putting unbearable yoke on the disciples. Acts 15:10 says, "Now therefore why tempt ye God, to put a yoke upon the neck of the disciples, which neither our fathers nor we were able to bear? 15:11 But we believe that through the grace of the LORD Jesus Christ we shall be saved, even as they."
The apostles, elders and the church at Jerusalem therefore concluded and wrote to other churches that they didn't give any command for anyone to keep the Law. Acts 15:24 says, "Forasmuch as we have heard, that certain which went out from us have troubled you with words, subverting your souls, saying, Ye must be circumcised, and keep the law:
to whom we gave no such commandment."
All those who still want to be justified by any practice from the Law has fallen from the grace (Galatians 5:4).
Galatians 2:16 say, "Knowing that a man is not justified by the works of the law, but by the faith of Jesus Christ, even we have believed in Jesus Christ, that we might be justified by the faith of Christ, and not by the works of the law: for by the works of the law shall no flesh be justified." Also Galatians 3:11 says, "But that no man is justified by the law in the sight of God, it is evident: for, The just shall live by faith."
All those practices (such as burning of incense, offering of animal sacrifices, observing of Sabbaths, giving of tithes, observing clean and unclean food, etc. ) under the Law that are practised today will justify no one. They must all be repented and forsaken!
For further study, kindly check for the book titled, Christian and Tithes via
https://selar.co/m/Jorab