Yo Yo Christianity
I think the Bible speaks about how God desires us to be once we become Christians and a part of the body of Christ(The Church) when Paul wrote to Timothy in His 2nd letter (2 Timothy 4:7 ) "I have fought the good fight, I have finished the race, I have kept the faith." Paul was near the end of His life on this earth and He was able to write with confidence these words. Can the same be said about you? Will you remain faithful to God all the days of your life and stop yo-yoing in and out of relationship with God or in and out of His church?
I think the problem for people who "yo-yo" is that they either never really took their salvation serious in the first place, so i'd question whether you are even saved? Or it could be that when you become a Christian you never got involved or plugged into your local church and because you weren't focused on serving the Lord you continue to put yourself first. Maybe the devil still has a foothold in your life and because of that you seem to always struggle because you live for the world, yourself, and not God.
Faith is like anything else, it needs attention and nurture to grow. Your Christian walk can be neglected, ignored, put on the back burner, or only used when you think you need it. What if you have a spouse that wasn't committed to their relationship with you and they were in and out of your life, always in turmoil, and inconsistent would that relationship be healthy? Last? Bring joy? Give you peace? Grow? Absolutely Not! Then why do we think we're going to grow as Christians if we treat God this way?
Being a Christian is a commitment and an eternal one at that! It means you, yes you, has to make the to read/study your bible, develop and grow your prayer life, and be faithful in attendance, service, giving, worship, and activity in the body of Christ(that is your local church). If you don't make an effort and a commitment to Christ and His Church you will always struggle, be in and out of church, blame God, make excuses, and be just like a yo yo.
That is why Paul also told the Philippian church members in Philippians 2:12 "continue to work out your salvation with fear and trembling" because your faith and eternity are your responsibility. Our salvation is solely based on what Jesus Christ did for us and not anything we've done or can do. However, our salvation is always based on our faith and faithfulness. We should not gamble away or give up our salvation because we lack commitment, we won't truly surrender to Jesus, or because we won't take the steps necessary to grow and mature in our faith.
Don't be a yo yo Christian, be faithful, stay faithful. Be proactive and productive in your relationship with God. Be committed and stay committed. Your salvation and eternity are too valuable to not stick with it!