Can a Christian lose their salvation?

No.

A truly saved born-again Christian cannot lose their salvation and go to hell. Once you are saved you are always saved. Jesus Christ will not take back His salvation even if we fall short. That said, we should strive to live holy lives that are well pleasing to God.

Explanation

Let’s look at some Bible verses to clear things up.

First off, let’s take a look at one of the most popular verses in all the Bible. In (John 3:16 KJV), Jesus proclaims to all the world that if you believe on the Son (Him) you will not perish but have everlasting life. Since God cannot lie, we must accept Jesus’ words as truth. His words promise eternal life to them that believe, not something temporary.

For God so loved the world, that he gave his only begotten Son, that whosoever believeth in him should not perish, but have everlasting life.

(John 3:16 KJV)

In hope of eternal life, which God, that cannot lie, promised before the world began;

(Titus 1:2 KJV)

We must also remember that our salvation is a gift from God paid for by Jesus Christ through His death, burial, and resurrection three days later. Jesus’ shed blood reconciles us to God giving us eternal life and peace with God. Jesus paid the sin debt in full to all, and offers the gift of eternal life to anyone who will accept it.

For by grace are ye saved through faith; and that not of yourselves: it is the gift of God:
Not of works, lest any man should boast.

(Ephesians 2:8-9 KJV)

Moreover, brethren, I declare unto you the gospel which I preached unto you, which also ye have received, and wherein ye stand; By which also ye are saved, if ye keep in memory what I preached unto you, unless ye have believed in vain. For I delivered unto you first of all that which I also received, how that Christ died for our sins according to the scriptures; And that he was buried, and that he rose again the third day according to the scriptures:

(1 Corinthians 15:1-4 KJV)