Justification by faith became the chief teaching of the reformation, and both luther and calvin believe in this doctrine. briefly explain the doctrine of justification.

The justification of faith doctrine is that God judges people based on their faith, not based on any other personal achievement or merit. This means that those justified have divine righteousness imputed upon them according to Christ's own merit which is infinite according to the Bible. If you become one with faith and with Christ you will be justified.