Some Christian groups claim that they are already saved, any one who has fellowship with them won't sin any more. Is it true ?
Salvation is a long process. It is true that objectively we are saved by the death and resurrection of Jesus and by our faith in Jesus Christ. But subjectively our salvation depends on our striving for the same. That is why St. Paul teaches, "work out your own salvation with fear and trembling; for it is God who works in you both to will and to do for His good pleasure" (PhI. 2:12-13). "Brethren, I do not couldn't myself to have apprehended; but one thing I do, forgetting those things which are behind and reaching forward to those things which are ahead, I press towards the goal for the prize of the upward call of God in Christ Jesus" (PhI. 3:13-14). Sanctification is 'already' and 'yet' (Cf. 1Cor 1 :2).1 came to call the sinners, Jesus said (Lk. 9: 56; Mt. 18: 11) Jesus established is Church to sanctify the sinners. He awaits their conversion and not their destruction. Though the church is holy (Eph. 5: 26-27), till the end of the world there will be sinners, striving for holiness. The parable of the wheat and weeds elucidates this fact (Mt 13:24-30, 36-43). So even those who think they stand, may take head lest they fall (1 Cor. 10: 12). There is a precaution in Peter's words. "If the righteous one is scarcely saved, where will the ungodly and the sinner appear" (1 Pet. 4: 18; Pros 11 :31). "For if, after they have escaped the pollutions of the world through the knowledge of the Lord and Saviour Jesus Christ, they are again entangled in them and overcome, the latter end is worse than the beginning" (2 Pet 2:20) So we should work out our salvation with fear and trembling. "For, we have become partakers of Christ if we hold our beginning confidence steadfast to the end" (Heb.3:14). Only Jesus is the true way that leads to eternal life (Jn.14:6). Those who have accepted Jesus as Saviour, have to walk with Jesus, as he walks in the way of the Father. "He who says he abides in Him ought himself also to walk just as he walked" (1 Jn. 2:6). Once you have reached the finishing point (Father) passing over your death, you have attained salvation.