"Christ is become of no effect unto you, whosoever of you are justified by the law; ye are fallen from grace". Galatians 5:4
The Apostle warns the people that once they had accepted salvation by grace through faith, if they went back to working out their salvation according to the law they had "fallen from grace".
We are saved by faith in what Jesus did at the cross. Salvation is the gift of God. We don't earn it. We can't work hard enough to obtain it. It is given by grace. It is unmerited. If it is received by grace, then it is also kept by grace. If we try to keep it any other way, then we have "fallen from grace". "Are ye so foolish? having begun in the Spirit, are ye now made perfect by the flesh?". (Galatians 3:3)
Grace is not a license; it is a gift. You can't do enough good works to stay saved-- although we should be doing works which cause our lights to shine and bring glory to our Father in heaven.
You can't be holy enough to stay saved-- although we are to live holy lives.
You can't be religious enough to stay saved-- although we should be tending to what we consider our religious duties: church attendance, Bible reading, fasting and prayer.
If you are trying to be saved through your own goodness and works, then you won't receive the gift of eternal life-- it is given by grace. If you are trying to stay saved by your own goodness and works, then you have fallen from grace. It ceases to be about what Jesus did and becomes about what you can do.
Have a great day. If you are trying to stay saved through your works, you are "fallen from grace".