Can you lose your salvation?
YES!
Romans 6:23 KJV tells us, For the wages of sin is death; but the gift of God is eternal life through Jesus Christ our Lord. Additionally, Hebrews 10:26-27 KJV says, For if we sin wilfully after that we have received the knowledge of the truth, there remaineth no more sacrifice for sins, [27] But a certain fearful looking for of judgment and fiery indignation, which shall devour the adversaries.
While no one can remove us from the Father’s hand (John 10:27-29), we can willingly let go and walk away from Him by continuing in sin. Jesus states in John 8:34 . . . Verily, verily, I say unto you, Whosoever committeth sin is the servant of sin. He also said in Matthew 6:24 KJV, No man can serve two masters: for either he will hate the one, and love the other; or else he will hold to the one, and despise the other. Ye cannot serve God and mammon.
Finally, if salvation is a gift, like any other gift it can be refused, rejected, and even despised. If you accept and respect Christ’s sacrifice, you will strive to walk in the light by living righteously and eschewing (shunning) sin.