So does the Bible say that we can lose our salvation?
Well, Jesus tells us that it can happen:
Rev 3:14 "And to the angel of the church in Laodicea write: 'The words of the Amen, the faithful and true witness, the beginning of God’s creation.
Rev 3:15 "'I know your works: you are neither cold nor hot. Would that you were either cold or hot!
Rev 3:16 So, because you are lukewarm, and neither hot nor cold, I will spit you out of my mouth.
St. Paul also warns us:
Rom 11:17 But if some of the branches were broken off, and you, although a wild olive shoot, were grafted in among the others and now share in the nourishing root of the olive tree,
Rom 11:18 do not be arrogant toward the branches. If you are, remember it is not you who support the root, but the root that supports you.
Rom 11:19 Then you will say, "Branches were broken off so that I might be grafted in."
Rom 11:20 That is true. They were broken off because of their unbelief, but you stand fast through faith. So do not become proud, but stand in awe.
Rom 11:21 For if God did not spare the natural branches, neither will he spare you.
Rom 11:22 Note then the kindness and the severity of God: severity toward those who have fallen, but God’s kindness to you, provided you continue in his kindness. Otherwise you too will be cut off.
Rom 11:23 And even they, if they do not continue in their unbelief, will be grafted in, for God has the power to graft them in again.
The tree is the tree of life, of salvation. The Jews represent the naturl branches that God cut off. The grafted on branches are the gentiles. Note that verse 22 very clearly says that these gentiles can be cut off again. If a person does not continue in God’s kindness, he can lose his salvation.
1Co 9:24 Do you not know that in a race all the runners compete, but only one receives the prize? So run that you may obtain it.
1Co 9:25 Every athlete exercises self-control in all things. They do it to receive a perishable wreath, but we an imperishable.
1Co 9:26 So I do not run aimlessly; I do not box as one beating the air.
1Co 9:27 But I discipline my body and keep it under control, lest after preaching to others I myself should be disqualified.
Here St. Paul exhorts his readers to live their Christian lives well. He says at the very end that even he can lose his salvation. If St. Paul can lose his salvation, I can too.
Here’s my favorite:
Phi 3:8 Indeed, I count everything as loss because of the surpassing worth of knowing Christ Jesus my Lord. For his sake I have suffered the loss of all things and count them as rubbish, in order that I may gain Christ
Phi 3:9 and be found in him, not having a righteousness of my own that comes from the law, but that which comes through faith in Christ, the righteousness from God that depends on faith–
Phi 3:10 that I may know him and the power of his resurrection, and may share his sufferings, becoming like him in his death,
Phi 3:11 that by any means possible I may attain the resurrection from the dead.
Phi 3:12 Not that I have already obtained this or am already perfect, but I press on to make it my own, because Christ Jesus has made me his own.
Phi 3:13 Brothers, I do not consider that I have made it my own. But one thing I do: forgetting what lies behind and straining forward to what lies ahead,
Phi 3:14 I press on toward the goal for the prize of the upward call of God in Christ Jesus.
Phi 3:15 Let those of us who are mature think this way, and if in anything you think otherwise, God will reveal that also to you.
In verse 11, St. Paul says that he hopes to somehow attain salvation. In verse 12, he very explicitly says he has not already attained salvation. In verse 15he says that this is how mature Christians think, and indicates that if anyone thinks otherwise they are immature and still need to learn it, but says that God will reveal it to them.
There are more, but this is a sample.