God has not promised that Christians will be exempt from problems not at all. After all, even Jesus "was despised and rejected by men, a man of sorrows, and familiar with suffering" (Isaiah 53:3). Why should we expect anything less?
But listen: It does make a difference whether or not we believe in God and are truly trusting Him and walking with Him! When we know Christ, we have an inner resource to help us through the difficult times and that is God Himself. Which is better, to face life's problems alone and with no one to help us and encourage us? Or to face them with Christ in our hearts, helping us and guiding us? The Bible says, "I can do everything through him who gives me strength" (Philippians 4:13).
But there is another reason you need Christ, and it is a very serious one. Someday you will die and face God to give an account of your life. Which is better to face that day alone, with no hope of Heaven because you have turned your back on Christ? Or to face it with Christ, who loves you and gave Himself for you?
Don't let anything your pride, your self-reliance, your sins, anything keep you from Christ. Instead, reach out in faith and commit your life to Him.