You’ve to develop certain habits in order to see the grace of God in other people also. Habits are the small decisions you make and actions you perform every day. What you spend time thinking about and doing each day ultimately forms the person you are, the things you believe, the personality that you portray towards yourself and how you see others also.
In Mark 8:23-25 Jesus heals a blind man, and he asked him if he saw ought. The man looked up, and said, I see men as trees, walking. He put his hands again upon his eyes, and made him look up: and he was restored, and saw every man clearly. Develop a habit to see others as who they really are, not as trees. But see God’s grace upon them.
When it comes to dealing with other believers first know this principle; "What God hath cleansed, that call not thou common" Acts 10:15.
Peter said, “Forasmuch then as God gave them the like gift as he did unto us, who believed on the Lord Jesus Christ; what was I, that I could withstand God?" Acts 11:17.
Before you doubt or question a fellow believer’s faith, first ask yourself, what or who am I, that I can withstand God in them?
Remember God also gave them the like gift as he did unto us, who believed on the Lord Jesus Christ. Barnabas came to Antioch and saw the grace of God among the people and was glad, "and exhorted them all, that with purpose of heart they would cleave unto the Lord" Acts 11:23. There are people who when they visit your church they cause great havoc, but Barnabas was not like that. He saw the grace of God among them; that others were Christians just as he was also, that they also received the word of God, and had like gifts as they also had.
Sometimes believers forget that we eat the same spiritual meat and drink the same spiritual drink. They’ve a tendency of "preaching the word to none but unto the Jews only." But 2 Corinthians 4:13 says, "We having the same spirit of faith, according as it is written, I believed, and therefore have I spoken; we also believe, and therefore speak; Knowing that he which raised up the Lord Jesus shall raise up us also by Jesus, and shall present us with you."
What’s pastor saying? I’m saying see God’s grace in all. Romans 8:16-17 says, "The Spirit itself beareth witness with our spirit, that we are the children of God: And if children, then heirs; heirs of God, and joint-heirs with Christ; if so be that we suffer with him, that we may be also glorified together."