How can we distinguish between a true believer and someone who claims to be Christian but are not truly converted.
None of the Disciples knew that Judas was a Devil, they thought he was a true Christian.
There are some who live as true Christians for most of their lives, only to be exposed as false believers by committing some grievous sin that no true believer would commit.
There are also those who became Christians at an older age after living very sinful lives, they also have a strong testimony but we can't be sure that they are genuine either.
I don't think it's possible to distinguish the true believers from the false, only God knows who they are. So I believe we need to treat everyone as brothers and sisters until they prove otherwise.
It is hard to tell how genuine someone is when in the presence of the saints, for they will be on their best behavior, and if they act up in front of the saints they surely do not care.
Jesus said the Pharisees appeared righteous, beautiful on the outside, but inside were full of dead men's bones, and uncleaness.
Unless you know someone personally you might not know all that they do, which might be hypocritical.
There are many Christians that do not get it that we have to hate sin, and not want sin, before the Spirit will lead us, for it not then we are led of the flesh.
Which the Bible says some have a form of godliness, but deny the power thereof (the Spirit that gives them the power to overcome sin), ever learning but never able to come to the knowledge of the truth, which they believe that they are right with God despite their sins, for they do not think they can beat sins.
It is really a matter of belief, and we might sin, but all sin can be forgiven, but it is our attitude towards sin, which there can be a pleasure in sin such as having great wealth, or at least a good amount of money above our needs, and material things, being able to enjoy life like travel, and cruises, but then it falls under the category of the love of money which neglects the poor and needy.
And some find pleasure in alcohol, and drugs, and worldly entertainment,and belittling people liking the arrogancy of it, and such things.
And we might sin for we might want to enjoy one of those fleshy pleasures, but as a saint we are supposed to hate sin, and not want sin, but all sin can be forgiven.
The Bible says the Lord know them that are His having this seal, which this is what seals the saints, and the way they are led of the Spirit, that everyone that names the name of Christ depart from iniquity.
And a Spirit led life will not fulfill the lusts of the flesh.
So we can abstain from sin, and sin does affect our relationship with God, so our attitude should be to know that sin separates us from God, and we are not right if we hold unto sin, and someone with that attitude will gave a far greater chance at abstaining from sin, and if they do sin they will get rid of it and keep moving forward, and they will feel shame when they do wrong.
But some do not have that attitude which Jesus said not everybody that says Lord, Lord, will enter heaven because they were workers of iniquity, because they held unto sin, and people usually do that because they think they are still right with God despite their sins, for they think they cannot beat sins, and sin daily, but by the Spirit we can abstain from sin if we hate sin, so there is no excuse
Which you would have a better chance at knowing who is genuine and who is not in Christlike behavior, and not hypocrisy, by their attitude concerning sin, for the ones that say they can abstain from sin, and sin does affect their relationship with God, and they cannot hold unto sin and be right with God, you will know that the person would most likely be genuine for those you do not know their lifestyle personally.
Not saying they might not sin, but it will give you a better chance at knowing their personal life, then if they are among the saints and acting right, for basically everybody will act right then.
If they have the attitude they cannot abstain from sin, and sin daily, and sin does not affect their relationship with God, then you have a better chance at knowing they might be holding unto sin, and most likely they will hold unto sin, although they would not be as bad as the world for they would have some kind of Christlike behavior.
When it comes to love of Jesus though, many are thankful what Jesus Has done for them, and love Him, whether they have the right or wrong attitude.
But God says they truly do not love Him if they have the wrong attitude because God hates sin, and if we do not hate sin then we would be going against the character of God who hates sin.
But those that have the wrong belief really think they love God, in which they do, but God's definition is different concerning love than what some people think it is, for He will not bypass holding unto sin, so sin does affect our relationship with God, where some say it does not.
I think what is important is to find a Church that preaches the right attitude concerning being led of the Spirit, and being Christlike, for the hypocrisy will not be as bad, and they will for the most part be on the level, and show the love of Christ more towards people.
But God said in a great house there are some to honor, and some to dishonor, which He said there will be some hypocrites, but it is still a great house, so people should not be discouraged concerning if there are hypocrites, but the main thing is to find a Church that preaches the right attitude for then the hypocrisy should be low, and it would probably be in very minor things.
For I did attend a Church that did preach the right attitude when I lived in another city, and I knew many of them personally, and also knowing their lifestyle, and hung around some of them, and believe me they did a great job at acting like Christ all to my delight, for they really were sincere to do what is right, for that is what the Church taught and they said, it is truth.
