The world is changing fast today, and it often seems that the historical Christian faith is under attack from many directions and worst of all sometimes the historical faith is attacked from inside the church.
When the storms of life spring up, we can seem like ships that are tossed to and fro by the wind and waves and we feel that we are in danger of being shipwrecked. We must remember to hold fast to God’s word and his promises which are like an anchor to our soul and keep us fixed and safe no matter what the storms of life try to do to us.
Talking of 'holding fast' several years ago my son-in-law asked me to join him going on the the world's fastest roller coaster, the Formula Rossa  in Ferrari World, Abu Dhabi. I had to hang on for dear life, I lost a shoe, and my hair was standing on end. In hindsight this gave me gave some insight into what it means to hold fast.
What does it mean to hold fast to something?
“Holding fast” in the Bible means to hold your position or fix your gaze and not lose sight of what is true. So this means that our attention -and therefore our actions- are fixed on God. After that, we need to obey His instructions — which is really the next logical step if your gaze and heart are locked on God.
There are a number of scriptures that tell us to hold fast. The key scripture for this study is found in Hebrews 10:19-25.
Hebrews 10:19 Having therefore, brethren, boldness to enter into the holiest by the blood of Jesus,20 By a new and living way, which he hath consecrated for us, through the veil, that is to say, his flesh; 21 And having an high priest over the house of God.22 Let us draw near with a true heart in full assurance of faith, having our hearts sprinkled from an evil conscience, and our bodies washed with pure water.
God has made a new and living way into his presence for believers and encourages us to draw near to him confidently knowing that our hearts and minds have been cleansed from sin.
23 Let us hold fast the profession of our faith  without wavering; (for he is faithful that promised;)
Based on these wonderful facts, what must we do now? We must not lose our nerve but rather declare the hope that we hold in eternal life because that is what Jesus Christ promised us and he is completely faithful to his word. No need to waver, no need to doubt because We can trust Jesus, we can trust all his promises to us.
24 And let us consider one another to provoke  unto love and to good works:
The practical results of our unwavering faith and hope in Christ should be that we set an example to the Christian community stimulating each other to show love in action which results in Holy Spirit led good works such as charity, compassion, and kindnesses.
25 Not forsaking the assembling of ourselves together , as the manner of some is; but exhorting one another: and so much the more, as ye see the day approaching.
Another practical outworking of holding fast to our confession of faith is that we will actively encourage the believers to assemble and thus be mutually encouraged.
As Christians we need to know what to hold fast to:
1 Thessalonians 5:21 Prove all things: hold fast to that which is good.
Prove all things means don’t just accept everything you hear, test it against the bible, discuss it with people you trust. Once you believe something is true then hold fast on it.
Proverbs 4:13 Take fast hold of instruction; let her not go: keep her for she is thy life.
We receive instruction from the bible and from our pastors/ ministers, we need to grasp that which is good teaching and apply it to our lives for it keeps us living right.
2 Timothy 1:13 Hold fast the form of sound words, which you have heard from me, in faith and love which is in Christ Jesus.
Paul tells Timothy to hold fast to the good doctrine that he had been taught by Paul for it was given in the faith and love of Jesus Christ.
Revelation 2:25 and 3:11 Jesus tells two  of the seven churches to hold fast what they have that no one steals their crown.
To the faithful remnant in Thyatira who had not fallen into Satan’s depths Jesus tells them to hang on to receive their great rewards. To the faithful in Philadelphia Jesus says he knows their good works , and that they have a little strength left , they have kept his word and have not denied his name.
The Lord is calling each one of us today to hold fast onto all that is good in our lives.
Hold fast onto the Lord himself.
Hold fast to the word of God in the Bible.
Hold fast onto all the good Christian practices that you have learned over the years.
Hold fast onto your own personal faith in Christ.
Footnotes  Ferrari World Abu Dhabi for example is home to a pair of record-breaking roller coasters, and one of them, the Formula Rossa, just happens to hold the Guinness World Record for the World’s Fastest Rollercoaster — clocking in with a blistering max speed of 240 km/h and traveling 52 meters into the sky in just 4.9 seconds.  Ellicott’s Commentary: Let us hold fast the profession/confession of the (Christian) hope (rather than faith). Hope here refers to eternal life as God’s children and heirs of Christ which we can rely upon since God is faithful to all his promises.  Original meaning of ‘to provoke’ means ‘to arouse,’ ’to excite,’ or ‘to call to action’ our fellow believers.  Hebrews 10:25 The most obvious interpretation of ‘assembling’ is ‘for public worship’ see Barnes Notes on the Bible.  The churches of Thyatira and Philadelphia, respectively.