When we trust in the risen and crucified Lord Jesus Christ alone as our Saviour.
John 7:37-39
37 In the last day, that great day of the feast, Jesus stood and cried, saying, If any man thirst, let him come unto me, and drink.
38 He that believeth on me, as the scripture hath said, out of his belly shall flow rivers of living water.
39 (But this spake he of the Spirit, which they that believe on him should receive: for the Holy Ghost was not yet given; because that Jesus was not yet glorified.)
Ephesians 1:12-14
King James Version (KJV)
12 That we should be to the praise of his glory, who first trusted in Christ.
13 In whom ye also trusted, after that ye heard the word of truth, the gospel of your salvation: in whom also after that ye believed, ye were sealed with that Holy Spirit of promise,
14 Which is the earnest of our inheritance until the redemption of the purchased possession, unto the praise of his glory.