"And the Lord added to their number daily those who were being saved." Acts 2:47
Salvation is present continuous. Christians are in the process of being saved as long as they believe and remain in Christ.
"Though you have not seen him, you love him; and even though you do not see him now, you believe in him and are filled with an inexpressible and glorious joy, for you are receiving the goal of your faith, the salvation of your souls." 1 Peter 1:8,9
You are receiving the salvation of your soul. Salvation is present continuous.
"Once you were alienated from God and were enemies in your minds because of your evil behaviour. But now he has reconciled you by Christ's physical body through death to present you holy in his sight, without blemish and free from accusation - if you continue in your faith, established and firm, not moved from the hope held out in the gospel." Col. 1:21-23
As the believer continues to believe, he continues to receive salvation.
"And now, dear children, continue in him, so that when he appears we may be confident and unashamed before him at his coming." 1 John 2:28
The believer continues in Christ as he continues to trust in God's grace. By faith the believer enters into this grace and it is by faith that the believer must continue to live in this grace until Christ comes again!
"After beginning with the Spirit, are you now trying to attain your goal by human effort?" Gal. 3:3
"..if you confess with your mouth, 'Jesus is Lord,' and believe in your heart that God raised him from the dead, you will be saved. For it is with your heart that you believe and are justified, and it is with your mouth that you confess and are saved." Romans 10:9,10
As the believer continues to believe and continues to confess he is saved and will be saved.
Salvation is union with God that is realised (worked out - Phil. 2:12) by daily and abiding fellowship with Him.
"This is how we know we are in him: whoever claims to live in him must walk as Jesus did." 1 John 2:6
Your initial "prayer of faith" to be saved has gained you entrance into the grace in which you now stand. To stand firm, you need to continue to have faith by continuing to abide in Christ. Your abiding in Christ will bear fruit which will give you confidence on the day He returns.
"...as we live in God, our love grows more perfect. So we will not be afraid on the day of judgment, but we can face him with confidence because we live like Jesus here in this world." 1 John 4:17
"...those who obey God's word truly show how completely they love him. That is how we know we are living in him." 1 John 2:5
Are you being saved?
"For the message of the cross is foolishness to those who are perishing, but to us who are being saved it is the power of God." 1 Cor. 1:18
"Examine yourselves to see whether you are in the faith; test yourselves. Do you not realise that Christ Jesus is in you - unless, of course, you fail the test?" 2 Cor. 13:5