continue to believe

Heb 3:14

For we have become partakers of Christ if we hold the beginning of our confidence steadfast to the end,

Romans 11:20-22

20 Well said. Because of unbelief they were broken off, and you stand by faith. Do not be haughty, but fear. 21 For if God did not spare the natural branches, He may not spare you either. 22 Therefore consider the goodness and severity of God: on those who fell, severity; but toward you, goodness, if you continue in His goodness. Otherwise you also will be cut off.

1 Tim 2:15

Nevertheless she will be saved in childbearing if they continue in faith, love, and holiness, with self-control.

1 Cor 15:1-2

1 Moreover, brethren, I declare to you the gospel which I preached to you, which also you received and in which you stand, 2 by which also you are saved, if you hold fast that word which I preached to you--unless you believed in vain.