(1 Corinthians 1:9)

What does it mean for God to be faithful? The word itself means to be trust worthy. Paul uses it in 1 Corinthians 1:8-9 to say that God is trustworthy to finish what He started in those believers’ lives.

Are your circumstances hard at the moment? It may be because of your sin and worldliness (James 4:1-2; 1 John 2:15-17)? Are you neither salt nor light? God our Father, is faithful to discipline His children to bring them back into a right relationship with Him (Hebrews 12:4-11). He does this because he loves His children and wants what is best for them. What is the best for us? Obedience to the word of God. 
Your difficulties could be because of your stand for Christ (1 Peter 4:12-13). Be encouraged that if you are facing slander and abuse because of your obedience to God, then know that you are no different than Jesus (1 Peter 2:21). Be encouraged, for God is faithful to never desert you or forsake you as you go through these trials (Heb 13:5).
Or God could be ordaining difficulties in order to refine you like gold (1 Peter 1:7). He knows that the heat of fiery trials removes the dross in our lives and gives us a purer devotion to Him. Do not despair when your life is turned upside down. God is making you like Jesus. He is faithful to cause all things to work together for our ultimate good-- conformity to the image of Christ (Rom 8:29). 

God has not changed. He is always faithful to accomplish His will in the lives of His people.