We need to work together, to ensure we all get to Heaven.
Getting to Heaven is as simple as choosing to worship Jesus Christ as the Son of God and accepting His gift of atonement for our sins....working together or separately is never going to ensure anyone gets to Heaven. We will be judged by our works as Christians when we get there but our salvation from sin and into eternal life is assured with our faith and belief in Christ's sacrifice for our sin.
Pointing out other people's sin is a sticky widget...I do believe Christ dealt with that issue a couple of times with the whole "ye who is without sin, cast the first stone" and again with the one about pointing out the moat in another's eye when you have a beam in your own. Judgement and discernment and the difference between the two is an oft argued point in the Bible. Rather than focus on another's sin we are to edify one another in our good works performed in Christ's name.
As for communion, I don't know that I've ever seen anywhere that it says that people who are out of the will of God in their lives could not take it....it does mention that it is to be taken in rememberance of Christ and His sacrifice for us and that we should be doing this with all reverance. Is there a verse stating that they should not partake?
Many a church have split over such issues as who is doing what in their lives and serving in the church....and the Satan wins that battle each and every time. Sin is sin, folks, with no sin being more or less weighty than another in God's eyes. All our righteousness is as filthy rags as was stated earlier from Isaiah. I believe that means that it is very hard for one christian to point to another's sin and state that mine is less and his is more, God, so why is he allowed to serve in your house? God does not appoint these people to these stations, man does.
I have never seen anywhere in the Bible that states that gambling leads to sin or that gambling is thought of as a sin, though I have been taught all my life that it was sinful. I do remember where it states that drunkeness is not desirable because it leads to sinful doings but I've only ever heard mention of gambling when the Roman soldiers cast lots for Christ's clothing prior to the crucifixion.
I know the Bible states clearly who should or should not be serving as elders or deacons in a church and that is pretty clear, to be sure. Is it our job to monitor their lives? I think we are to be careful of fellowshipping with those who are doing these things and pray for them.
Would I leave a church because the pastor condones open sinfulness in the church leaders? Maybe not for that thing in particular but eventually....because that sort of thing starts at the top and works it's way down and shows up in all aspects and doctrines of the church by the time it is done. It is hard to fellowship with those who are living out of the will of God and it shouldn't be hard work to fellowship with other believers. It should be joyful and uplifting to learn and worship with those who are united in their spiritual goals. I just left a church after 5 years because I kept waiting to see the love of God in those people and it never really transpired....and yes, the deacons weren't anyone that I would elect as a deacon, according to the Scriptural guidelines.
I don't condone the sin of those who are doing it and I try to avoid fellowship with those actively sinning in the sight of God, as it states in the Word that we are to be careful that we don't get pulled into that lifestyle by simply being so close to it.