We do not decide for Christ. Human decision-making is one of the weakest elements of the human being.
Adam and Eve relied on their own limited thinking, rather than listening to the wisdom of God; thus they ate the Forbidden Fruit, and fell from God's grace, passing on to the human race a sin nature separating us from God.
Instead, it is God who calls us through Jesus Christ, and we heed the call by faith (Faith comes by hearing, and hearing by the word of God (Romans 10:17)
"And he said, Therefore said I unto you, that no man can come unto me, except it were given unto him of my Father." (John 6:65)
And
"Ye have not chosen me, but I have chosen you, and ordained you, that ye should go and bring forth fruit, and that your fruit should remain: that whatsoever ye shall ask of the Father in my name, he may give it you."
Jesus has made it very clear — if there was a decision, He made it for us.
Now, this line of truth does not support universal salvation, for "By grace you are saved, through faith" (Ephesians 2:8) and "All men have not faith." (2 Thessalonians 3:2)
Grace has been extended to the whole world by Christ's death on the Cross, yet every man must receive this grace by faith. It is not something that we work for, not even the faith to receive this grace — everything is gift, gift from God.
Therefore, we do not choose Him, we do not even choose salvation, strictly speaking, but rather it is given to us, and therefore we receive it.
This clearly articulated doctrine in scripture refutes Kierkegaard's dependence on human will, on human choice, a point he demonstrates repeatedly in both his pseudonymous and spiritual discourses published under his own name.