I don't believe that a life long works based effort is necessary in order to stay saved. I do believe though that a person that genuinely has faith will have some sort of works in their lives...if they don't have fruit then there is something wrong with the tree
1Pe 2:12 Having your conversation honest among the Gentiles: that, whereas they speak against you as evildoers, they may by your good works, which they shall behold, glorify God in the day of visitation.
2Ti 3:15 And that from a child thou hast known the holy Scriptures, which are able to make thee wise unto salvation through faith which is in Christ Jesus.
2Ti 3:16 All Scripture is given by inspiration of God, and is profitable for doctrine, for reproof, for correction, for instruction in righteousness:
2Ti 3:17 That the man of God may be perfect, thoroughly furnished unto all good works.
Eph 2:9 Not of works, lest any man should boast.
Eph 2:10 For we are his workmanship, created in Christ Jesus unto good works, which God hath before ordained that we should walk in them.