>>510103215No. The proof a person is saved is that they have believed the gospel. And we are told to live the Christian life by faith, not by works. We have faith in Jesus Christ. If we instead believe we must have works, then where is our faith? It would be in our own works, our own performance, rather than in what Christ has already done for us. Christ's shed blood has washed away all of our sins: past, present AND future. Amen!
Now once we are saved, we become "born again," as in we are indwelled with the Holy Spirit who preserves us and guides us. We are to walk in faith and let the Spirit do the work in and through us. Any good that we do is NOT our own, but rather is a reflection of Christ. All glory belongs to Christ and Him alone. But we are all on our own path as guided by the Spirit. We cannot judge another brother/sister for not living up to whatever standard we might set. The standard belongs solely to God, and all of us that have believed the gospel are now part of the body of Christ, and no one can pluck us out of God's hand.
The Bible does not teach perseverance, but rather preservation! And that preservation comes by God alone not by our own effort.
But yes, we should live lives that are righteous and honor God, so as to best draw others to Christ. And the Spirit can help with that if we yield to Him. But we will never be sinless in this life. And regardless of what sins we do or what good we do, we are all saved and we are all equal in the body (for those that have believed the gospel of course).