Acts 9:31 (NKJV): 31 Then the churches throughout all Judea, Galilee, and Samaria had peace and were edified. And walking in the fear of the Lord and in the comfort of the Holy Spirit, they were multiplied.
And
Philippians 2:12 (NKJV): 12 Therefore, my beloved, as you have always obeyed, not as in my presence only, but now much more in my absence, work out your own salvation with fear and trembling;

There is something about having a healthy fear of the Lord. The Lord, in fact, is the only thing we should be afraid of. He is the only one that determines our salvation. Only His judgements are final. Should we no longer have fear because of God’s grace? Wasn’t Paul and the “churches throughout all Judea, Galilee, and Samaria” also walking in grace and yet had that healthy fear.
God’s grace is free and there’s nothing we can pay to obtain it or pay back. However, our relationship with our living God has to be maintained or we may lose our salvation.
John 15:1–2 (NKJV):
15 “I am the true vine, and My Father is the vinedresser. 2 Every branch in Me that does not bear fruit He takes away

And again

Hebrews 6:4–6 (NKJV): 4 For it is impossible for those who were once enlightened, and have tasted the heavenly gift, and have become partakers of the Holy Spirit, 5 and have tasted the good word of God and the powers of the age to come, 6 if they fall away, to renew them again to repentance, since they crucify again for themselves the Son of God, and put Him to an open shame.
But lets not forget also the prodigal son. He left his father’s house and later returned. If you have fear of “blowing it” Go to the lord and “work out your salvation with fear and trembling.”