Sometimes the simplest explanation is the best explanation. Sometimes bad teaching is nothing more than taking simple truths and making them complicated. When the early church began to see pagan Gentiles converted, false teachers swooped in to make things complicated. The false teachers said that salvation took more than believing in Jesus. They said you also needed to be circumcised.
The church held a conference to figure out the truth. It was Peter who spoke up during the conference, reminding the elders that he was the first one to see Gentiles converted. While visiting Cornelius’ house (Acts 10), Peter was simply giving a Bible study when the Holy Spirit fell on the Gentiles in attendance, and they began speaking in tongues. It was obvious they had been saved, and it happened when they simply believed the word of God. They trusted God’s grace. They believed Jesus died for their sins. Peter reminded the conference, “But we believe that through the grace of the Lord Jesus Christ we shall be saved in the same manner as they.” (Acts 15:11)
Some churches have decided to redefine “grace” as something that you receive only when you come through their doors and participate in their rituals. Yet all Peter did was to speak to Cornelius and his friends about Jesus. They believed. They were saved. Be careful about complicating what God makes simple.